Puricelli et al (2022) offered a "state of the art report" on the gut-brain-immune axis in autism spectrum disorders:
"Even though the emergence of scientific interest in gut microbiota is quite recent, the knowledge of gut bacteria role and importance in human health has been known for centuries. References to sour milk or fermented foods date back even to the Bible and, already in fourth century China, one of the treatments for diarrhea or food poisoning implied the use of the so-called 'yellow soup,' also known with the more pretentious name of 'golden syrup,' which consisted of fecal material from healthy subjects. A similar habit was described among African Beduins, used to consuming the feces of their camels to fight dysentery, a practice which would be used hundreds of years later by the German soldiers of the African troops to recover from dysentery in the early 1940s. In the fifteenth century, the Italian anatomist Acquapendente coined the concept of transfaunation' to refer to the transfer of fecal material from healthy to sick animals, thus founding a new therapeutic approach also in veterinary medicine, while the 'God's smallest creatures' observed by Antoni van Leeuwenhoek (1632-1723) in his own feces provided real evidence that microorganisms could be detected in human stools. The largest contribution to the field of intestinal microbiota was probably given by the Russian Nobel prize Metchnikoff (1845- 1916), who went beyond the simple use of fecal matter to treat some gastrointestinal disorders by observing (and experiencing on himself) the impact of daily consumption of fermented dairy products on improved health and longevity in Bulgarian peasants, thus pointing out the role of fecal microbiota also in prevention strategies. However, it was only in 1965 that the word "probiotics" was first introduced by Lilly and Stillwell and later better defined by Parker as 'live microbial supplements which beneficially affect the host animal by improving its microbial balance'.
https://www.researchgate.net/journal/Frontiers-in-Psychiatry-1664-0640/publication/358312140_The_Gut-Brain-Immune_Axis_in_Autism_Spectrum_Disorders_A_State-of-Art_Report/links/66486ae522a7f16b4f33fff0/The-Gut-Brain-Immune-Axis-in-Autism-Spectrum-Disorders-A-State-of-Art-Report.pdf?_tp=eyJjb250ZXh0Ijp7ImZpcnN0UGFnZSI6Il9kaXJlY3QiLCJwYWdlIjoicHVibGljYXRpb25Eb3dubG9hZCIsInByZXZpb3VzUGFnZSI6InB1YmxpY2F0aW9uIn19 [5810]
The brain is but one thing connected to the gut. An overview:
Misiak et al (2020) have a more detailed look at the gut-HPA axis:
"Overview of mechanisms linking the gut microbiota and the HPA axis activity. The gut microbial alterations and increased intestinal permeability (1) lead to a release of various mediators, such as pro-inflammatory cytokines, small bioactive molecules, prostaglandins, microbial antigens and ileal corticosterone, as well as the mobilization of stem/progenitor cells that pass through the blood-brain barrier and activate the HPA axis (2). However, some of these mediators, including short-chain fatty acids (SCFAs) may attenuate the HPA axis response. Another mechanism of the HPA axis activation is related to the release of neurotransmitters by some bacteria that interact with vagal afferents (3). Emerging evidence also indicates an opposite association, i.e., the HPA axis activation can contribute to the gut dysbiosis and altered permeability (4). Abbreviations: ACTH - adrenocorticotrophic hormone; ClpB - caseinolytic peptidase B; IL-1 - interleukin-1, IL-6 - interleukin-6, LPS - lipopolysaccharide; SCFAs - short-chain fatty acids; TNF-α - tumor necrosis factor-α.
It cannot be ruled out that the association between the gut microbiota and the HPA axis also follows an opposite direction. Indeed, there is evidence that abnormal solicitation of the HPA axis during the brain development can impact microbial colonization and visceral sensitivity (Pellissier and Bonaz, 2017). This direction of causality has been proposed based on studies on irritable bowel syndrome. According to studies in this field, cortisol can directly activate resident immune cells and extrinsic primary afferents in the gastrointestinal tract (Moloney et al., 2016). Notably, it has been demonstrated that the prevalence of irritable bowel syndrome is significantly higher in patients with mood and psychotic disorders compared to the general population (Gupta et al., 1997; Lee et al., 2015). Finally, there is evidence from animal model studies that stress-related HPA axis response may increase the gut permeability. Indeed, crowding stress has been found to increase colonic expression of the receptors for the corticotrophic-releasing factor (CRF) type 1 in rats (Vicario et al., 2012). Exposure to water avoidance stress has been shown to exacerbate small bowel injury and gut permeability induced by non-steroidal anti-inflammatory drugs in mice. However, administration of mifepristone can attenuate this effect (Yoshikawa et al., 2017). The association between the HPA axis activation and the gut permeability has also been demonstrated in humans. Vanuytsel et al. (2014) revealed that the effect of public speech stressor on gut permeability appears only in men who present with increased cortisol levels."
https://www.sciencedirect.com/science/article/pii/S0278584620302670?via%3Dihub [3824]
In 2022 McGuinness et al published "A systematic review of gut microbiota composition in observational studies of major depressive disorder, bipolar disorder and schizophrenia":
"Gut microbiota—the symbiotic bacteria that live within our gastrointestinal (GI) system—act as 'metabolic machinery'. They influence many aspects of physiology via neural, hormonal and immunological pathways, so much so that some describe the gut microbiome as a 'virtual organ'. The interaction of the gut microbiota and central nervous system (CNS) is referred to as the 'microbiota-gut-brain axis'. Although gut bacteria assist with the maintenance of health, they can also disrupt homeostatic regulation and may influence the aetiology and pathophysiology of many diseases, including mental disorders."
https://www.nature.com/articles/s41380-022-01456-3 [4653]
Another 2022 review "The role of the gut microbiome in diet and exercise effects on cognition: A review of the intervention literature" by Canadian researchers Koblinsky et al also introduces the topic."The gut microbiome is modifed by factors such as diet and exercise, and targeting the microbiome through lifestyle modifcation may be a valid strategy for lowering dementia risk. The gut microbiome consists of all microorganisms, bacteria, viruses, protozoa, and fungi, and their cumulative genome within the GI tract. The microbiota in the GI tract comprised primarily 4 main phyla: Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria. They play an important role in nutrient and mineral absorption, and synthesis of enzymes, vitamins, amino acids, and neurotransmitters. A well-functioning microbial environment also produces metabolites such as short-chain fatty acids (SCFAs; e.g. acetate, propionate, and butyrate), which promote epithelial barrier integrity, modulation of the immune system, and protection against pathogens. A healthy gut microbiome is generally characterized by a high diversity of bacterial communities and is maintained by a symbiotic relationship between pathogenic and nonpathogenic bacteria, and host-derived factors (eg, mucins, antimicrobial peptides, and immunoglobulins). Gut microbial imbalances, referred to as dysbiosis, are implicated in the development of metabolic, autoimmune, and neurological diseases. Dysbiosis can result from aging, poor diet, antibiotics, or infections and is associated with increased intestinal permeability and inflammation). A dysbiotic intestinal environment can negatively affect the brain via the gut-brain axis. The gut-brain axis refers to communication between the intestinal environment and the brain via neural pathways (vagus nerve), endocrine signaling (hypothalamus-pituitary-adrenal [HPA] axis), and the immune system (cytokines). Microbial dysbiosis leads to increased gut permeability and the release of endotoxins (eg, lipopolysaccharide [LPS]) into the bloodstream triggering a neural immune response. The gut communicates its dysbiotic state with the brain via the vagus nerve causing increased HPA axis activity and the release of cortisol and proinflammatory cytokines. Chronic high cortisol and circulating proinflammatory cytokines can impair the blood-brain barrier and promote atrophy and neuroinflammation, affecting brain health and cognition. Microbial dysbiosis is associated with impaired cognition and is observed in individuals with AD. A diverse, well-functioning microbial environment is associated with improved learning/memory and behavioral fexibility."
and
"Supporting the mediating the role of the microbiome are microbiota changes that precede cognitive changes, antibiotic elimination of cognitive effects related to diet, microbiota transplant effects, and potential mechanistic links such as SCFA, BDNF, and inflammatory changes. Associations between altered microbiota and cognition were also frequently observed. In particular, bacteria from the Clostridia class and Bacteroidales order, such as Lachnospiraceae, Ruminococcaceae, Coprobacter, and Rikenella, as well as Lactobacillus and Bifdobacterium genera."
Rodent studies have limitations:
"A major limitation of rodent research is the narrow selection of cognitive tests. Spatial and object recognition are most always reported due to the frequent use of maze testing and fear conditioning paradigms. Thus, little is known about other cognitive domains, which can be differently impaired in humans experiencing dementia. Human trials provide the opportunity to comprehensively study cognition through neuropsychological assessment and the use of advanced measurement techniques such as MRI."
and
"In contrast to Western-style diets, interventions encompassing features of the MED diet, and uptake of exercise were associated with improved microbiota diversity, increased SCFA production, and reduced local and systemic inflammation. The evidence is mainly derived from rodent studies; however, one large MED diet intervention found diet-associated microbiota changes to be correlated with cognitive performance in older adults."
A future trial design is suggested in the authors' Figure 3.
https://academic.oup.com/biomedgerontology/advance-article/doi/10.1093/gerona/glac166/6670844 [1656]
In 2017 Vogt et al analysed microbiomes in AD and non-AD seniors, finding Firmicutes were decreased and Bacteroidetes increased in the AD group:
"With respect to dementia, a recent study in cognitively impaired elderly participants investigated a limited number of pro- and anti-inflammatory gut bacterial taxa and found altered abundance in individuals with positive amyloid positron emission tomography (PET) imaging. In addition, recent studies in transgenic mouse models of AD have demonstrated that manipulating gut microbiota can influence cerebral amyloid deposition. However, to date there have been no comprehensive surveys of whole gut microbiota in humans with AD. In this study, we performed bacterial 16S ribosomal RNA (rRNA) gene sequencing of DNA isolated from fecal samples in order to characterize the gut microbial communities in individuals with and without a clinical diagnosis of dementia due to AD. In addition, we examined the relationship between gut microbiota and AD pathology as measured by cerebrospinal fluid (CSF) biomarkers of AD."
They decided:
"AD is Associated with Changes in the Gut Microbiome
The composition of the gut microbiome was characterized using traditional ecological measures including richness (the number of unique OTUs present in a participant), alpha diversity (the richness and abundance of OTUs within each participant), and beta diversity (the similarity or difference in composition between participants). For microbiome richness estimates, we used the Abundance-based coverage estimator (ACE) and Chao1; these metrics use non-parametric modeling to calculate a conservative estimate of total OTU richness for each participant. The microbiome of AD participants had reduced richness, with both ACE and Chao1 significantly decreased in the AD group compared to the Control group (t-test; ACE: DF = 48, t = 3.05, p = 0.004; Chao1: DF = 48, t = 2.98, p = 0.004) (Supplementary Fig. S2). For alpha diversity metrics, we used the Inverse Simpson and Shannon Indexes, and Faith's Phylogenetic Diversity (PD), an alpha diversity metric that also incorporates phylogenetic relationships. While there was a trend towards a decrease in the Inverse Simpson Index between Control and AD groups (Mann-Whitney; U = 227.0, p = 0.097), both the Shannon Index and Faith's PD were significantly decreased in AD participants compared to Control participants (t-test; Shannon: DF = 48, t = 2.44, p = 0.019, PD: DF = 48, t = 2.59, p = 0.013) (Fig. 1A, Supplementary Fig. S2). With respect to beta diversity, Bray-Curtis dissimilarity and UniFrac analysis (weighted and unweighted) demonstrated compositional differences in the microbiome between AD and Control groups (PERMANOVA, Bray-Curtis: F = 2.87, p < 0.001, weighted UniFrac: F = 3.84, p < 0.001; unweighted UniFrac: F = 2.60, p < 0.005) (Fig. 1B, Supplementary Fig. S3)."
https://europepmc.org/article/med/29051531 [4869]
According to Șerban et al (2025)...
"ECS dysfunction appears to drive chronic disease states within the body; the lack of signaling drives synaptic downregulation, immune dysregulation, and breakdown of epithelial barriers. For example, neurodegenerative diseases, such as Alzheimer’s or Parkinson’s disease, demonstrate the links between ECS dysregulation and accelerating synaptic degeneration, neuroinflammation, and, possibly, oxidative stress. Likewise, in the gastrointestinal tract, dysfunctional ECS signaling in IBD was shown to break down normal epithelial barrier function, thus sustaining gut inflammation. The ECS habitat is strongly implicated in metabolic diseases and insulin resistance, obesity, and systemic inflammation.
"Therapeutic modulation of the ECS occurs through its integrated control over three major body systems, i.e., the nervous, immune, and gastrointestinal systems. The main ways to modulate the ECS include using CB2 receptor agonists to suppress neuroinflammation; using FAAH and MAGL inhibitors to elevate levels of endocannabinoids; and microbiota-directed treatments to enhance gut-brain-immune equilibrium."
https://www.mdpi.com/1422-0067/26/22/11132 [5835]
In conjunction with evidence that microbiome abnormalities (dysbiosis) significantly contribute to the progression of Alzheimer's disease (AD) [4866] and that the latter can be transferred from AD patients to adult rats, producing AD-like symptoms in them [4867], a large longitudinal study by Walker et al (2019) shows that aging is better prevented than reversed, and obviously the earlier the better [4868].
From Prajapati et al (2025):
"In this study, we used a probiotics cocktail that consisted of 5 Lactobacillus and 5 Enterococcus. We tested the efficacy of a well-characterized, human-origin probiotics cocktail proven effective in modulating both mouse and human microbiomes, reducing gut permeability and inflammation cascade. To observe the prophylactic treatment effect of probiotics cocktail we used around 2-months-old amyloid precursor protein (APP)/ presenilin-1 (PS1) strains (APP/PS1) of mice and fed them probiotics for up to 6 months. This timeline was chosen taking consideration of Bao et al. (2020), who treated two-month-old mice for four months. Further, they reported that six-month-old APP/PS1 mice exhibited spatial learning and memory deficits, accompanied by increased neuroinflammation, compared to C57 wild-type mice26. Similarly, Zhu et al. (2017), reported that the APP/PS1 mice show significant memory deficits and Aβ pathology at 5-months of age and worsened with age, reflecting the progressive nature of AD27. Further, we selected the hippocampus for analysis of pathologies because that brain region is typically where pathological changes associated with AD first manifest before spreading to other parts of the brain. These changes include the buildup of amyloid plaques and neurofibrillary tangles, characteristics of the disease. Cognitive deterioration, the result of these alterations, interfere with neuronal function28,29. Thus, hippocampus is crucial for early pathogenesis as well as for prophylactic treatment of AD. In this study the prophylactic treatment with probiotics cocktail showed promising effects in modulating this intricate cascade of the gut-brain axis and reducing the progression of AD pathology in a humanized APP/PS1 AD mouse model."
https://www.nature.com/articles/s41598-024-84780-8 [4866]
From "Microbiota from Alzheimer's patients induce deficits in cognition and hippocampal neurogenesis." by Grabrucker et al (2023):
"We found impairments in behaviours reliant on adult hippocampal neurogenesis, an essential process for certain memory functions and mood, resulting from Alzheimer's patient transplants. Notably, the severity of impairments correlated with clinical cognitive scores in donor patients. Discrete changes in the rat caecal and hippocampal metabolome were also evident. As hippocampal neurogenesis cannot be measured in living humans but is modulated by the circulatory systemic environment, we assessed the impact of the Alzheimer's systemic environment on proxy neurogenesis readouts. Serum from Alzheimer's patients decreased neurogenesis in human cells in vitro and were associated with cognitive scores and key microbial genera.
"Our findings reveal for the first time, that Alzheimer's symptoms can be transferred to a healthy young organism via the gut microbiota, confirming a causal role of gut microbiota in Alzheimer's disease, and highlight hippocampal neurogenesis as a converging central cellular process regulating systemic circulatory and gut-mediated factors in Alzheimer's."
https://academic.oup.com/brain/article/146/12/4916/7308687?login=false [4867]
"A total of 12,336 participants (baseline age 56.8 [5.7], 21% black, 56% women) were included. After adjusting for demographic variables, vascular risk factors, and comorbidities, each standard deviation (SD) increase in midlife inflammation composite score was associated with an additional 20-year decline of −0.035 SD (95% confidence interval: −0.062 to −0.007) on the cognitive composite score. We found a similar association between each SD increase in midlife CRP level and additional 20-year cognitive decline (−0.038 SD, 95% confidence interval: −0.057 to −0.019). Participants with a midlife inflammation composite score in the top quartile had a 7.8% steeper cognitive decline, compared to participants in the lowest quartile; CRP in the top quartile was associated with an 11.6% steeper cognitive decline. In cognitive domain-specific analyses, elevated midlife inflammatory markers were most consistently associated with declines in memory. Results were similar after adjusting for attrition using inverse probability weighting.
"Conclusions
Our findings highlight what may be an early pathogenic role for systemic inflammation as a driver of cognitive decline in the decades leading up to older adulthood."
https://pmc.ncbi.nlm.nih.gov/articles/PMC6511107/ [4868]
According to Zhu et al (2022) the human colonic microenvironment is disturbed by an unavoidable economic poison.
"Gut microbiota may affect host physiology by producing specific metabolites. The important and best-studied microbial metabolites are short-chain fatty acids (SCFAs). SCFAs are the end-product of microbial fermentation of dietary fibers and have been implicated in regulating energy metabolism, immune system and cell proliferation (Hu et al., 2018; Koh et al., 2016; Smith et al., 2013). It has been well documented that a decrease in SCFA production is associated with type 2 diabetes mellitus (T2DM) and obesity (Zhao et al., 2018). Dietary SCFAs supplementation protect against high-fat diet-induced metabolic abnormalities in mice (den Besten et al., 2015). Thus, the role of SCFAs as a potential factor in modulating health and disease is crucial and essential."
https://www.sciencedirect.com/science/article/abs/pii/S0269749121019631 [3608]
and
"Fluoride Ingestion Induces Formation of Unusual Macromolecular Complexes in Gut Lumen Which Retard Absorption of Essential Minerals and Trace Elements by Chelation"
https://link.springer.com/article/10.1007/s12011-024-04403-1 [3851]
Martin et al (2024) trained mice on an auditory task. As they gradually learned to complete the perceptual learning task, the researchers stimulated their vagus nerve using a tiny electrode they have developed. Concurrently, they also recorded activity in the animals' auditory cortex (involved in processing sounds), as well as in the locus coeruleus of the brainstem and the basal forebrain, two regions implicated in attention. Stimulation of the nerve made the mice smarter, revealing in broad terms the mechanism by which gut health produces neuroplasticity.
"Perception can be refined by experience, up to certain limits. It is unclear whether perceptual limits are absolute or could be partially overcome via enhanced neuromodulation and/or plasticity. Recent studies suggest that peripheral nerve stimulation, specifically vagus nerve stimulation (VNS), can alter neural activity and augment experience-dependent plasticity, although little is known about central mechanisms recruited by VNS. Here we developed an auditory discrimination task for mice implanted with a VNS electrode. VNS applied during behavior gradually improved discrimination abilities beyond the level achieved by training alone. Two-photon imaging revealed VNS induced changes to auditory cortical responses and activated cortically projecting cholinergic axons. Anatomical and optogenetic experiments indicated that VNS can enhance task performance through activation of the central cholinergic system. These results highlight the importance of cholinergic modulation for the efficacy of VNS and may contribute to further refinement of VNS methodology for clinical conditions."
https://www.nature.com/articles/s41593-024-01767-4 [3609]
https://medicalxpress.com/news/2024-10-vagus-nerve-perceptual-mice.html [3610]
In a 2021 review, Siomek-Gorecka et al in Bydgoszcz, Poland,
"...connect gathered knowledge from three emerging fields—genetics, epigenetics, and nutrition—to form an amazing triangle relating to alcohol use disorder."
"Alcohol abuse modifies the structure of chromatin and modulates gene expression through epigenetic changes. In a feedback loop, this neural remodeling conversely reinforces the abuse of alcohol. This is hypothesized to move alcohol abuse through the stages that eventually lead to addiction."
Genes expected to play a role are alcohol dehydrogenase 1B (ADH1B) and aldehyde dehydrogenase 2 (ALDH2), the catalase CAT0262 t allele, catechol-O-methyltransferase (COMT), serotonin transporter gene HTT.
"Studies of patients with alcoholism have shown a significant increase in genomic DNA methylation in the whole blood, which was associated with decreased DNMT-3a and DNMT-3b mRNA levels. This observation suggests a feedback regulation of these enzymes by the increased DNA methylation. In addition, in this study, the authors observed a significant negative correlation between DNMT-3b expression and blood alcohol concentration. An increased DNA methylation in the medial pre-frontal cortex and decreased expression of proteins involved in synaptic neurotransmitter release were also shown in alcohol-dependent rats."
and
"In genomewide studies, methylation was found to be an important process in connection with alcohol abuse. In comparing alcoholics with their non-alcoholic siblings, the authors have found that several genes have altered methylation signatures, such as ALDH1L2 (aldehyde dehydrogenase gene), GABRP (GABA receptor gene), and GAD1 (glutamate decarboxylase gene), which are linked to the alcohol tolerance dopamine beta-hydroxylase gene (DBH). In their study, Bruckmann et al. have confirmed a genome-wide report of hypomethylation in the ganglioside-induced differentiation-associated protein 1 (GDAP1) gene and the association between the DNA methylation of this gene and the disease severity of 49 AUD patients. The authors have also observed that the hypomethylation of GDAP1 in patients was reversed during a short-term alcohol treatment program, and this may suggest that GDAP1 DNA methylation could serve as a potential biomarker for treatment outcomes. Another study has shown a significant association of hypermethylation in the 3'-protein-phosphatase-1G gene (PPM1G) with alcohol use disorder, as well as two established AUD risk factors—adolescent escalation of alcohol intake and impulsivity."
and
"Many studies have analyzed the influencing substances in food that may affect the nervous system and appetite reactions. These substances modulate the nervous system and nutritional behavior. Researchers have emphasized the role of the endogenous cannabinoid neuronal system in the regulation of food intake. This system includes receptors in areas of the central nervous system, such as the lateral hypothalamus, arcuate nucleus (nucleus caudatus), and paraventricular nucleus (nucleus paraventricularis), and in the reward system, e.g., experiences of hunger modulated by hormones, such as leptin, orexin, and endogenous opioids]. Cannabinoid receptors, CB1 and CB2, are located in two metabolic long- and short-term systems of nutrition regulation connected with the repletion of the digestive system. Cannabinoids intensify the rewarding potential of food intake. Animal model surveys have proved that the application of the receptor CB1 antagonist (Rimonabant, SR141716A) decreased the reward potential of eating sweets and alcohol consumption. Interestingly, it has been proved that not only do human or animal organisms include cannabinoids but that these substances are also components of food (exogenous cannabinoids, e.g., cacao, chocolate, and milk). This leads to the conclusion that food may include additional biochemical substances that may induce specific physiological reactions and behavior. It seems to be also possible that these substances may indirectly increase the risk of alcohol consumption by eliciting the desire to use alcohol or that, on the contrary, these substances may be protection factors supporting abstinence. Studies have also indicated that DNA methylation may occur due to the use of psychoactive substances, e.g., alcohol and exogenous cannabinoids. Researchers have emphasized interactions between ethanol and the cannabinoid system. Moreover, recent studies have shown that epigenetic changes that occur after alcohol consumption, together with cannabinoids, may act synergistically and lead to DNA methylation or histone modification. This in turn may lead to a modulation of apoptosis and synaptic plasticity. Some reports reveal the ability of cannabinoids to modify the neuronal and immune system via histone modification, such as H3 lysine methylations or the alteration of DNA methylation."
https://scholar.google.si/scholar_url?url=https://www.mdpi.com/1422-0067/22/8/4262/pdf&hl=en&sa=X&ei=df-kY9iRH8aSy9YPyI6P8AY&scisig=AAGBfm1DtPLb9WqRpX8Ev8S0XxIPv-pWRw&oi=scholarr [1910]
Lin et al (2022) assembled the known histone modifications in inflammatory diseases in their Table 2. H3 appears as a target in psoriasis, asthma, SV40, the human papillomavirus HPV, the hepatitis viruses HBV, HDV, HCV, human immunodeficiency virus HIV, and SARS-Cov-2.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8908311/ [4871]
Parira et al at Department of Immunology, Herbert Wertheim College of Medicine, Florida International University would like us to know about "Epigenetic Interactions between Alcohol and Cannabinergic Effects: Focus on Histone Modification and DNA Methylation" (2017):
"CB2 receptor knockout or apoptosis related gene ATG5 knockout mice were exposed to chronic ethanol followed by binge ethanol feeding showed that CB2 receptor activation in liver macrophages protects mice from alcohol-induced steatosis by blocking hepatic inflammation through an autophagy-dependent pathway. In human studies, cannabinoid signaling has been associated with alcohol exposure as recently reviewed in 2016. Exposure to ethanol increases the activity of the endocannabinoid system in the brain, leading to decreased CB1 binding and uncoupling that is directly associated with consumption of ethanol. Furthermore, a positron emission tomography imaging study revealed acute alcohol exposure in humans increased cerebral CB1 binding while chronic alcohol exposure caused a decrease in CB1 binding that is maintained even after abstinence for at least a month."
and
"Alcohol and its association with the endocannabinoid system, which is involved in reward signaling mechanism of the brain, has been studied quite extensively with cannabinoids and its receptors being explored as pharmacological drug targets for AUDs. The cannabinoid system appears to be important in regulating addiction by influencing retrograde signaling to suppress neurotransmitter release. This synaptic activity plays a role in the mechanism underlying addiction to substances of abuse including alcohol."
And now the most dogmatic use of the word "however"...ever.
"The adverse effects of alcohol and cannabinoid abuse are widely known; however, with the legalization of marijuana in some states and availability of medical marijuana, the potential of endogenous cannabinoids and their receptors to be of therapeutic significance is immense. From the review above, we can see a vast existing literature showing the connection between effects of alcohol and cannabinoid activity, such that cannabinoid receptor agonists and/or antagonists may be able to reverse alcohol's deleterious effects or reduce alcohol selfadministration. Understanding epigenetics may help us ultimately understand the connection between alcohol and endocannabinoid signaling mechanisms."
Of course the therapeutic potential has not been altered one iota by legalisation or MMLs. Even in retreat the tail is wagging the dogma.
https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC5515243&blobtype=pdf [1911]
Nair et al spelled it out in "Alcohol Versus Cannabinoids: A Review of Their Opposite Neuro-Immunomodulatory Effects and Future Therapeutic Potentials" (2015):
"cannabinoids and alcohol exert differential and opposite inflammatory effects as shown by the cytokine array profiles performed with monocyte-derived dendritic cells from alcohol, marijuana, and control donors (Figures 1 and 2)."
Here they are:
The second one is a little easier to take in
Now let's look more closely at some depressed rats, in whom Zikai Hao et al at Beijing University found that:
"administration of F. prausnitzii had preventive and therapeutic effects on CUMS-induced depression-like and anxiety-like behavior. In addition, F. prausnitzii administration could significantly prevent the reduction of the whole-body, femur and tibia BMD during the recovery phase. Moreover, the growth status of rats fed the F. prausnitzii was better than the rats by CUMS. And F. prausnitzii administration led to higher levels of SCFAs in the cecum and higher levels of cytokines interleukin-10 (IL-10) in the plasma, prevented the effects on corticosterone, C-reaction protein and cytokines interleukin-6 (IL-6) release induced by CUMS, changes that were associated with the effects seen on behavior. These results provide further evidence that gut microflora play a role in anxiety and depression."
https://www.sciencedirect.com/science/article/abs/pii/S0306453018312071 [762]
It had been the same for mice back in 2008:
In the forced-swimming test, IL-10-/- females displayed increased depressive-like behavior; importantly, this phenotype was reverted by the injection of IL-10. Moreover, mice overexpressing IL-10 presented a decreased depressive-like behavior. Despite the presence of a similar trend, male animals did not reach significant differences in depressive-like behavior. Assessment in the open-field showed that the absence of IL-10 decreased the percentage of time spent in the center of the arena in both male and female mice, while male animals overexpressing IL-10 revealed an opposite behavior. For both sexes, imbalance in IL-10 levels did not affect spatial reference memory. In conclusion, variations in IL-10 expression are associated with an altered depressive-like behavior, but do not influence cognitive performance. Interestingly, IL-10 imbalance produced more profound behavioral changes in females than in male animals. This is in accordance with clinical data demonstrating an increased susceptibility of women to mood disorders, suggesting an interplay between anti-inflammatory cytokines and sexual steroid.
https://repositorium.sdum.uminho.pt/bitstream/1822/8631/1/Mesquita%20JPR.pdf [1568]
Australian researchers explain the impact of the microbiome on mood:
"The field of psychiatry is somewhat unique in medicine in that the aetiology of mental disorders is largely unclear, and there are no robust biomarkers to aid in diagnosis or prognosis. This means that the differentiation between major mental disorders, such as mood and psychotic disorders, relies primarily on symptom presentation. Given the rapidly growing evidence base for the gut microbiota's influence on multiple systems and pathways that are known to be commonly dysregulated across these mental disorders, including inflammation and oxidative stress; tryptophan metabolism and the kynurenine pathway; mitochondrial dysfunction; neurotransmitters; brain plasticity and neurotrophic factors and metabolic processes, the gut and its resident bacteria are increasingly recognised as important research targets. Critically, the functional potential of different bacteria is increasingly understood, meaning that identification of key taxa that are differentially abundant in people with mental disorders and that influence these commonly dysregulated systems is an imperative. Such identification may afford opportunities for both understanding aetiology and identifying clinically useful biomarkers, as well as new targeted treatment strategies, including dietary changes, antibiotics, probiotic supplements and even faecal microbial transplants."
https://www.nature.com/articles/s41380-022-01456-3 [1048]
Wilson et al (2025) looked at "Long-term health outcomes in adolescents with obesity treated with faecal microbiota transplantation: 4-year follow-up":
"There was no difference in BMI between the two groups, after adjusting for sex, age, diet, and physical activity (−3.6 kg/m2, p = 0.095). However, FMT recipients showed clinical improvements in body composition and metabolic health compared to the placebo group. Specifically, FMT recipients had smaller waist circumference (−10.0 cm, p = 0.026), total body fat (−4.8%, p = 0.024), metabolic syndrome severity score (−0.58, p = 0.003), and systemic inflammation (−68% hs-CRP, p = 0.002) and higher levels of HDL cholesterol (0.16 mmol/L, p = 0.037). No group differences were observed in glucose markers, or other lipid parameters. Shotgun metagenomic sequencing revealed sustained long-term alterations in gut microbiome richness, composition and functional capacity, with persistence of donor-derived bacterial and bacteriophage strains. These findings highlight the potential relevance of FMT as a microbiome-augmenting intervention for obesity management and metabolic health, warranting further investigation."
https://www.nature.com/articles/s41467-025-62752-4 [5372]
Kwashiorkor, obesity, and behaviour consistent with autism have been produced with fecal microbial transplants into germ-free mice.
"Increased asthma risk was found in children born by cesarean section only if their gut microbiota at age one year still carried a cesarean section signature. No associations with asthma existed from the very early though more pronounced microbial perturbations.
'Even though a child is born by cesarean section and has an immense early microbial perturbation, this may not lead to a higher risk of asthma, if the microbiome matures sufficiently before age one year,' said Jakob Stokholm MD, PhD, senior researcher and leader of the microbiome group at COPSAC and first author on the study."
https://www.science.org/doi/10.1126/scitranslmed.aax9929 [1156]
It was not known in 2010 that maternal commensals could influence offspring even before birth by either method.
By 2016 Hu et al had shown that both bacteria-produced molecules and maternally derived antibodies appear to drive immune development in utero.
Noting that
"...a sharp rise in T1D incidence has been seen in recent years in genetically susceptible young children and individuals who do not carry high risk HLA [human leukocyte antigen] alleles and this has also taken place over a relatively short period of time. This strongly suggests that non-genetic factors, especially environmental factors influence disease development."
...they used two antibiotics, vancomycin and neomycin, that have very different functional features, to observe their influence on T1D development in the non-obese diabetic (NOD) mouse model:
"Environmental factors clearly influence the pathogenesis of Type 1 diabetes, an autoimmune disease. We have studied gut microbiota as important environmental agents that could affect the initiation or progression of type 1 diabetes especially in the prenatal period. We used neomycin, targeting mainly Gram negative or vancomycin, targeting mainly Gram positive bacteria, to treat pregnant NOD mothers and to study autoimmune diabetes development in their offspring. Neomycin-treated offspring were protected from diabetes, while vancomycin-treated offspring had accelerated diabetes development, and both antibiotics caused distinctly different shifts in gut microbiota composition compared with the offspring from untreated control mice. Our study demonstrated that neomycin treatment of pregnant mothers leads to generation of immunetolerogenic antigen-presenting cells (APCs) in the offspring and these APCs had reduced specific autoantigen-presenting function both in vitro and in vivo. Moreover, the protection from diabetes mediated by tolerogenic APCs was vertically transmissible to the second generation. In contrast, more diabetogenic inflammatory T cells were found in the lymphoid organs of the offspring from the vancomycin-treated pregnant mothers. This change however was not transmitted to the second generation. Our results suggested that prenatal exposure to antibiotic influenced gut bacterial composition at the earliest time point in life and is critical for consequent education of the immune system. As different bacteria can induce different immune responses, understanding these differences and how to generate self-tolerogenic APCs could be important for developing new therapy for type 1 diabetes."
The authors find it interesting that
"...more Bacteroidetes were found in neomycin-treated mice and more Firmicutes were found in vancomycin-treated mice (Fig.3A). Actinobacteria were significantly reduced in both neomycin- and vancomycin-treated breeding mothers compared to untreated mothers (Fig. 3B); however, we found an increase in Cyanobacteria in neomycin-treated breeding mothers compared to either vancomycin-treated mothers or untreated controls."
At 15 weeks
"the differences in the abundance of Proteobacteria seen in the mice prenatally exposed to vancomycin remained high even at 15 weeks old (Fig.3D), while Actinobacteria remained low (Fig.3D). In contrast, the abundance of Actinobacteria in the mice prenatally exposed to neomycin was elevated with age (Fig.3D). We also examined the overall G+/G− ratio in both Neo- and Van-treated mice. Although the Van group did not show differences compared with the untreated NOD group, a significant reduction was presented in the Neo group (Fig. 3E)."
https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC4958594&blobtype=pdf [2188]
Martín-Peláez et al in The Impact of Probiotics, Prebiotics, and Synbiotics during Pregnancy or Lactation on the Intestinal Microbiota of Children Born by Cesarean Section: A Systematic Review" (2022) found that...
"Probiotic, prebiotic, and synbiotic interventions led to beneficial gut microbiota in cesarean-delivered newborns, closer to that in vaginally delivered newborns, especially regarding Bifidobacterium colonization. This effect was more evident in breastfed infants. The studies indicate that this beneficial effect is achieved when the interventions begin soon after birth, especially the restoration of bifidobacterial population."
To finesse further:
"The studies indicate that the sooner the intervention begins, the more successful the effect achieved, since the first three months of life are a key window for GM recovery in C-section infants, especially regarding Bifidobacterium. In fact, most of the studies included in this review started the interventions immediately after birth, although the rest of the included studies found beneficial modifications of the GM of newborns even when beginning intervention later. These early interventions can restore the low Bifidobacterium presence in C-section infants within a week. The intervention period is also important. In the present review, although some authors state that a minimum of 3 months would be needed to restore the GM of C-section infants by using probiotic strains, we have found that shorter intervention durations are also effective."
https://www.mdpi.com/2072-6643/14/2/341 [3316]
Thus it would seem that long term consequences for society could turn upon the number of cesarean deliveries and the parent or neonatal staff's knowledge of this topic. How does this tie in with cannabis? Dysbiosis in adulthood might drive cannabis use. Disturbances in the gut-brain axis could influence behavioural problems.
Other considerations therefore enter into an evaluation of cannabis use during pregnancy. What if it is being used instead of antibiotics? Might this not lead to a better outcome, if not a better outcome than no need for either?
Alcohol has a negative effect on gut permeability and the microbiome. The offspring of drunk pregnant women might benefit from adding or substituting with cannabis. This, with or without a cesarean, can have consequences.
Such a choice is a complex interaction of forces individual to the personality of the person, in a very personal setting, and not readily susceptible to legal control.
We are unlikely to obtain any proof in humans about this one way or another for some time to come, if ever.
While FAS has been defined since 1973, no fetal cannabis syndrome has been identified.
The same cannot be said of a C-section syndrome, according to Sevelsted et al (2015):
"Mature children born by cesarean delivery were analyzed for risk of hospital contact for chronic immune diseases recorded in the Danish national registries in the 35-year period 1977-2012. Two million term children participated in the primary analysis. We studied childhood diseases with a suspected relation to a deviant immune-maturation and a debut at young age. The effect of cesarean delivery on childhood disease incidences were estimated by means of confounder-adjusted incidence rate ratios with 95% confidence intervals obtained in Poisson regression analyses.
"RESULTS:
Children delivered by cesarean delivery had significantly increased risk of asthma, systemic connective tissue disorders, juvenile arthritis, inflammatory bowel disease, immune deficiencies, and leukemia. No associations were found between cesarean delivery and type 1 diabetes, psoriasis, or celiac disease."
https://publications.aap.org/pediatrics/article-abstract/135/1/e92/52900/Cesarean-Section-and-Chronic-Immune-Disorders [3318]
Even FAS, whose phenotypic expression is plain enough, combines a moral and social construction with clinical features: in 1998 E M Armstrong of Ann Arbor's Department of Health Management and Policy found...
"...the medical literature on FAS is infused with moral rhetoric, including passages from classical mythology, philosophy, and the Bible."
And describes how:
"The recognition of a new disease or syndrome is sometimes the result of serendipity, but more often the result of determined investigation and scientific entrepreneurship. In the case of fetal alcohol syndrome, moral fervor powered the discovery as much as medical curiosity. Drinking during pregnancy—a social rather than a medical phenomenon—came to be considered a problem worthy of doctors' ever-finite attention through the work of moral entrepreneurs. Howard Becker first described 'moral entrepreneurship' in his 1963 book Outsiders (Becker, 1963). In his words, a moral entrepreneur is one who sees 'some evil which profoundly disturbs him' (p. 147) and who sets out to remedy the situation. Becker notes that while moral entrepreneurs are crusaders, on a holy mission, their crusades often have 'strong humanitarian overtones' (p. 148). The moral entrepreneur believes that if other people do what he thinks is right, 'it will be good for them' (p. 148). 'Moral crusaders typically want to help those beneath them to achieve a better status' (p. 149). They derive power not only from the legitimacy of their moral position, but from their own 'superior position in society' (p. 149). That is, moral entrepreneurs tend to be elites working to impress their moral vision on the rest of society. Becker cites prohibitionists and psychiatrists as typical moral entrepreneurs. In fact, Freidson has characterized the physician as an exemplary type of moral entrepreneur. Parsons (1975) has also noted the moral authority of the physician.
"Since Becker, several observers have noted instances of moral entrepreneurship resulting in the creation of new diseases or diagnostic categories. Stephen Pfohl (1977), for example, characterized the discovery of child abuse as an instance of moral entrepreneurship; Peter Conrad (1975) and Frances McCrea (1986) have analyzed the moral entrepreneurship in the construction of hyperkinesis and menopause, respectively. Allan Brandt (1990): p. 159) has described the way 'moral reformers'—who were epidemiologists and doctors as well—'equated moral dangers and health risks' in proving the causal link between cigarette smoking and lung cancer. In constructing a new diagnosis and by implication a social problem, doctors speak with unique authority: in our society, it is still primarily doctors who are granted the authority to identify a new disease. The medical-moral entrepreneurs who published on FAS thus held a formal medical mandate as well as a moral one."
https://www.sciencedirect.com/science/article/abs/pii/S0277953698003086?via%3Dihub [3317]
A 2024 systematic review of this sort of thing from Inchigolo et al at the University of Bari, Italy, displays a strengthening concern, with references:
"The importance of early microbial colonization in shaping long-term health outcomes cannot be overstated.
"The composition of the infant's GM during the first critical months of life is believed to exert a lasting influence on the individual's health trajectory.
"Emerging evidence suggests that deviations from the natural process of vaginal birth, such as through CS delivery, can contribute to alterations in the microbiota that may have far-reaching consequences.
"Disruptions in the establishment of a balanced and diverse microbiota composition have been implicated in various health conditions, including autoimmune disorders, metabolic syndrome, and even mental health disorders."
Quoting Wenqing Yang they say:
"While there were no differences in microbial diversity between cesarean and vaginally born infants on the third day, significant differences emerged on the seventh and twenty-eighth days."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10816971/ [3319]
Others are calmer:
"'We saw that many niches of the mother are important for the transmission of microbes, and if some of these pathways are blocked for one reason or another—in this case, we saw that happening with the cesarean section—then these microbes can still reach the infant through other paths,' says Dr de Steenhuijsen Piters.
"Regardless of birth route, the researchers found that approximately 58.5% of a baby's microbiome is derived from its mother. However, different maternal microbial communities contributed to different infant microbiomes. Cesarean-born babies received fewer microbes from their mother's vaginal and fecal microbiomes, but—seemingly in compensation—acquired more microbes from breastmilk."
"'It's a smart system, and it makes sense from an evolutionary perspective that these types of pathways are redundant to ensure that the child can begin life with the appropriate "starter kit,"' says Dr de Steenhuijsen Piters."
https://www.ed.ac.uk/inflammation-research/news-events/babies-receive-microbes-from-mothers [3322]
https://www.cell.com/cell-host-microbe/fulltext/S1931-3128(23)00043-4 [3323]
The group with the worst microbiome prognosis, by these measures, may be bottle-fed C-section babies with remote or obsessively clean parents.
Prior to conception, pre-implantation, as well as in utero or during, choosing cannabis can be positive for the microbiome. Regardless of the official verdict of the catholic church, choosing alcohol is always negative for it. [1906]
And lest we forget, the earliest known use of cannabis in labour was in AD 390. [2264].
Reports on this topic are unexpectedly thin. Postonogova et al asked 132 non-C-section mums-who-had-been what they thought about it all.
"The percentages of respondents who reported having epidural or intravenous analgesia were 83% (95% confidence interval [CI] 76-89) and 30% (95% CI 23-38), respectively, with 87% (95% CI 79-92) and 86% (95% CI 71-94) being satisfied. However, 34% (95% CI 26-43) of the respondents reported that they would consider the use of marijuana for labour pain. Of these, 25% (95% CI 14-41) had previously used marijuana for pain compared with 0% (95% CI 0-0) who had not, and 72% (95% CI 56-84) thought it acceptable to use marijuana non-medically compared with 35% (95% CI 26-47) who did not (P < 0.001 for both). The greatest worry was the effect of marijuana on the baby, with 26% (95% CI 19-34) being highly worried and 26% (95% CI 19-34) being extremely worried. Many women (60%; 95% CI 51-68) indicated a lack of knowledge of the side effects of marijuana in labour. However, 59% (95% CI 50-67) of respondents said they would feel comfortable discussing this topic with their obstetrician."
https://www.sciencedirect.com/science/article/abs/pii/S1701216319309594 [3320]
Studies found little difference between pregnant users and non-users, except slightly elevated dysfunctional labour, precipitate labour and meconium staining.
https://pubmed.ncbi.nlm.nih.gov/6617473/ [3321]
Other considerations therefore enter into an evaluation of cannabis use during pregnancy. What if it is being used instead of antibiotics? Might this not lead to a better outcome, if not a better outcome from a need for either? Alcohol has a negative effect on gut permeability and the microbiome. The offspring of drunk pregnant women might benefit from adding or substituting cannabis. We are unlikely to obtain any proof in humans about this one way or another for some time to come, if ever.
By 2019 FMT was being used successfully to treat critically ill patients, as reported by Dai et al, who infected seven (43.8%) patients with Acinetobacter baumannii, six (37.5%) with Pseudomonas aeruginosa, and four (25.0%) with Enterococcus aureus.
"Twenty critically ill patients with AAD underwent rescue FMT, and 18 of them were included for analysis. The mean of Acute Physiology and Chronic Health Evaluation (APACHE) II scores at intensive care unit (ICU) admission was 21.7 ± 8.3 (range 11-37). Thirteen patients received FMT through nasojejunal tube, four through gastroscopy, and one through enema. Patients were treated with four (4.2 ± 2.1, range 2-9) types of antibiotics before and during the onset of AAD. 38.9% (7/18) of patients had FMT-related AEs during follow-up, including increased diarrhea frequency, abdominal pain, increased serum amylase, and fever. Eight deaths unrelated to FMT occurred during follow-up. One hundred percent (2/2) of abdominal pain, 86.7% (13/15) of diarrhea, 69.2% (9/13) of abdominal distention, and 50% (1/2) of hematochezia were improved after FMT. 44.4% (8/18) of patients recovered from abdominal symptoms without recurrence and survived for a minimum of 12 weeks after being discharged from ICU."
https://d-nb.info/120476736X/34 [3276]
A 2021 letter to New Microbes and New Infections points to one important colonist:
"Faecalibacterium prausnitzii is functionally considered a significant microbiota since this species of microbiota is found in many animals and humans. Based on the Meta-analysis of the Human Intestinal Tract project reports, F. prausnitzii...is considered one of the most numerous anaerobic bacteria in the human gut microbiota. F. prausnitzii, is an acetate consumer that produces butyrate and bioactive anti-inflammatory molecules such as shikimic and salicylic acids.
"In that context, the change rate of F. prausnitzii in the gastrointestinal tracts is connected to multiple complications and syndromes; however the cause or a consequence of them is not understood clearly. The abundance of F. prausnitzii in faeces has been investigated in some diseases like irritable bowel syndrome, Crohn's disease, ulcerative colitis, type 2 diabetes, obesity, coeliac disease, self-limited colitis, atopic diseases, chronic idiopathic diarrhoea, acute appendicitis, neuroendocrine tumours of the mid gut, liver transplantation, colorectal cancer and other diseases. What is outstanding is the much research that has been done in patients with a lower relative abundance compared with healthy control. According to Gopalakrishnan et al., the existence of F. prausnitzii could raise the efficacy of immune checkpoint inhibitors in melanoma patients."
https://www.sciencedirect.com/science/article/pii/S2052297521000925?via%3Dihub [2189]
By December 2018, BMC Genomics was reporting:
"Faecalibacterium prausnitzii is a ubiquitous member of the human gut microbiome, constituting up to 15% of the total bacteria in the human gut."
and
"Two phylogroups of F. prausnitzii have been identified, with a decrease in phylogroup I being a more sensitive marker of intestinal inflammation. Much of the genomic and physiological data available to date was collected using phylogroup II strains. Little analysis of F. prausnitzii genomes has been performed so far and genetic differences between phylogroups I and II are poorly understood."
This therefore signals a new beginning. Previous research has been looking in the wrong place, in too little detail. Which Fitzgerald et al proceeded to explore in 31 genomes, revealing
"...a very low level of average nucleotide identity among F. prausnitzii genomes and a high level of genome plasticity. Two genomogroups can be separated based on differences in functional gene complement, albeit that this division does not fully agree with separation based on conserved gene phylogeny, highlighting the importance of horizontal gene transfer in shaping F. prausnitzii genomes."
...and remind us that:
"Butyric acid is one of the main metabolic end-products of F. prausnitzii fermentation. Microbiota-derived butyric acid is known to possess anti-inflammatory activity, as well as to serve as one of the main energy sources for colonocytes. In addition, F. prausnitzii has been shown to produce a number of substances with proven anti-inflammatory properties, including a 15 kDa proteinaceous "microbial anti-inflammatory molecule" (MAM) that was able to inhibit the NF-κB pathway in intestinal epithelial cells and prevent colitis in a murine IBD model. A capsule-like extracellular polymeric matrix has also been shown to suppress the inflammatory response in cultured dendritic cells and alleviate intestinal inflammation in a murine model of IBD."
It's a challenging read.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6295017/ [2191]
Researchers in the Netherlands, also in December 2018, add "The use of drugs such as proton pump inhibitors or laxatives, which are more often used by patients with IBD or IBS, has a large impact on the gut microbiota composition," says "Gut microbiota composition and functional changes in inflammatory bowel disease and irritable bowel syndrome".
Their Figure 2 shows the ups and downs in Crohn's, UC, and IBS.
F. prausnitzii belongs to the Ruminococcaceae family.
The team noted that the diversity of strains within beneficial bacterial species, such as Faecalibacterium prausnitzii, tended to wane in the guts of individuals with IBD or IBS relative to the unaffected controls. They also saw shifts in strain diversity for 21 bacterial species in individuals with Crohn's disease, compared to strain diversity changes in 15 species in those with ulcerative colitis and one species in the IBS group.
Here's their Figure 1F: "On average, as schematically depicted...controls had more Actinobacteria in their stool than did patients with IBD or IBS. Patients with IBS had more Firmicutes and less Bacteroidetes than did controls. In contrast, patients with IBD had less Firmicutes and more Bacteroidetes than did controls."
https://cris.maastrichtuniversity.nl/ws/files/89547170/Keszthelyi_2018_Gut_micobiota_composition_and_functional.pdf [2192]
For Microbial Pathogenesis Vol 149 December 2020:
"The expression of the relative abundances, which have been proposed as a possible indicator of gut dysbiosis in adult subjects, is considered as the ratio of F. prausnitzii/E. coli. Based on the reported results in some studies, F. prausnitzii is an indicator and an active contributor to intestinal health and the maintenance of gut homeostasis due to its ubiquity and immunomodulatory properties."
and
"The variation of F. prausnitzii population is related to modulation of eight urinary metabolites."
and
"Modulation of gut microbiota composition probably decreases the risk of many complications."
and
"Recently, the importance of F. prausnitzii in human health has been recognized by the research community."
https://www.sciencedirect.com/science/article/abs/pii/S0882401020307105?via%3Dihub [2190]
The same year, 2020, saw the Kim et al paper "Co-Culture with Bifidobacterium catenulatum Improves the Growth, Gut Colonization, and Butyrate Production of Faecalibacterium prausnitzii: In Vitro and In Vivo Studies" from Seoul National University.
"Faecalibacterium prausnitzii is a major commensal bacterium in the human gut. It produces short-chain fatty acids that promote intestinal health. However, the bacterium is extremely oxygen-sensitive, making it difficult to develop as a probiotic. To facilitate practical application of F. prausnitzii, we investigated factors that affect its growth and mammalian gut colonization. We evaluated cross-feeding interactions between F. prausnitzii and seven Bifidobacterium strains, and the anti-inflammatory properties of bacterial metabolites produced in co-culture, in vitro and in vivo. Co-culture of F. prausnitzii and Bifidobacterium catenulatum, with fructooligosaccharides as an energy source, resulted in the greatest viable cell-count and butyrate production increases. Further, the co-culture supernatant reduced the amount of proinflammatory cytokines produced by HT-29 cells and RAW 264.7 macrophages, an effect that was similar to that of butyrate. Furthermore, feeding mice both Faecalibacterium and Bifidobacterium enhanced F. prausnitzii gut colonization. Finally, feeding the co-culture supernatant decreased interleukin 8 levels in the colon and increased butyrate levels in the cecum in the dextran sodium sulfate-induced colitis mouse model. These observations indicate that the Faecalibacterium-Bifidobacterium co-culture exerts an anti-inflammatory effect by promoting F. prausnitzii survival and short-chain fatty acid production, with possible implications for the treatment of inflammatory bowel disease."
As to the mechanics of this:
"It is well-established that F. prausnitzii consumes acetate produced by Bifidobacteria and produces butyrate. In the current study, we confirmed a decrease in acetate levels and an increase in butyrate levels after 24 h of culture, compared with those after 9 h. F. prausnitzii requires a carbohydrate energy source for growth and butyrate formation, and bifidobacteria do not produce butyrate. The observed changes in acetate and butyrate levels in co-cultures in the YCFOS medium not supplemented with SCFA suggest that the growth of F. prausnitzii was supported by acetate supplied by Bifidobacterium, while the two bacteria competed for FOS [fructooligosaccharides] present in the culture medium."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7285360/ [3277]
Mexican research pointing to a "gut-joint axis" by which dysbiosis influences rheumatic disease also discuss F. prausnitzii:
"In the mouse gut, colonic Treg induced by Clostridium bacteria are vital players in gut homeostasis and prevent colitis (Alameddine et al., 2019). In the human colon microbiota, Clostridium IV Faecalibacterium prausnitzii induces the formation of Treg cells via the activation of dendritic cells and causes the secretion of IL-10 by T cells (Garabatos and Santamaria, 2022; Wang et al., 2022b). Another gut bacteria, Bacteroides fragilis, via its carbohydrate antigen polysaccharide A (PSA), may promote the differentiation of Treg in vitro or mice through dendritic cell modulation. Furthermore, PSA stimulates Treg cells and suppresses Th17 cell responses through an IL-2-dependent mechanism (Horta-Baas et al., 2017).
In humans, gut bacteria have been shown to influence the polarization of T-cell subpopulations. At the phylum level, Verrucomicrobiota showed a positive correlation with the absolute number of Tregs, while Firmicutes showed a negative correlation with the total number of Th17 cells in RA patients (Wang et al., 2022a)."
and
"Results on differences between fecal SCFAs concentrations in RA patients compared to HCs [healthy controls] demonstrate a reduced amount of SCFAs in samples of RA patients. In one study, levels of acetate, propionate, butyrate, and valerate were decreased in RA patients (Yao et al., 2022). In another study, early-RA patients presented significantly reduced propionate levels (Marazzato et al., 2022). Similarly, Takahashi et al. and Rosser et al. showed that the stool concentrations of butyrate were significantly lower in new-onset RA patients and inactive RA patients, respectively (Rosser et al., 2020; Takahashi et al., 2020). He et al. reported significant reductions in serum and stool butyrate levels in RA patients (He et al., 2022). Conversely, in Rosser et al. study, there was no difference in propionate or butyrate but a significant increase in acetate levels in serum samples of RA patients compared to HCs."
And they offer these illustrations:
Romero-Figueroa et al (2023) assessed that:
"Progress in the understanding of the gut microbiome and RA. has been remarkable in the last decade. In vitro and in vivo experiments revealed that gut dysbiosis could shape the immune system and cause persistent immune inflammatory responses. Furthermore, gut dysbiosis could induce alterations in intestinal permeability, which have been found to predate arthritis onset. In contrast, metabolites derived from the intestinal microbiota have an immunomodulatory and anti-inflammatory effect. However, the precise underlying mechanisms by which gut dysbiosis induces the development of arthritis remain elusive. This review aimed to highlight the mechanisms by which gut dysbiosis could contribute to the pathogenesis of RA. The overall data showed that gut dysbiosis could contribute to RA pathogenesis by multiple pathways, including alterations in gut barrier function, molecular mimicry, gut dysbiosis influences the activation and the differentiation of innate and acquired immune cells, cross-talk between gut microbiota-derived metabolites and immune cells, and alterations in the microenvironment. The relative weight of each of these mechanisms in RA pathogenesis remains uncertain. Recent studies showed a substantial role for gut microbiota-derived metabolites pathway, especially butyrate, in the RA pathogenesis."
https://pmc.ncbi.nlm.nih.gov/articles/PMC9911673/ [5258]
Controlling for depression, risk-taking, maternal education, and alcohol, tobacco, and other drug use, Skumlien et al (2022) found more anhedonia in cannabis non-users. In "Anhedonia, Apathy, Pleasure, and Effort-Based Decision-Making in Adult and Adolescent Cannabis Users and Controls"...
"We used data from the 'CannTeen' study. Participants were 274 adult (26-29 years) and adolescent (16-17 years) cannabis users (1-7 d/wk use in the past 3 months) and gender- and age-matched controls. Anhedonia was measured with the Snaith-Hamilton Pleasure Scale (n = 274), and apathy was measured with the Apathy Evaluation Scale (n = 215). Effort-based decision-making for reward was measured with the Physical Effort task (n = 139), and subjective wanting and liking of rewards was measured with the novel Real Reward Pleasure task (n = 137).
"Results
Controls had higher levels of anhedonia than cannabis users (F1,258 = 5.35, P = .02, η p2 = .02). There were no other significant effects of user-group and no significant user-group*age-group interactions. Null findings were supported by post hoc Bayesian analyses.
"Conclusion
Our results suggest that cannabis use at a frequency of 3 to 4 d/wk is not associated with apathy, effort-based decision-making for reward, reward wanting, or reward liking in adults or adolescents. Cannabis users had lower anhedonia than controls, albeit at a small effect size. These findings are not consistent with the hypothesis that non-acute cannabis use is associated with amotivation."
Looking back at the surprisingly sparse science of anhedonia and apathy, they note:
"Previous studies using similar behavioral assessments of motivation have yielded mixed evidence for altered effort-based decision-making for reward in cannabis users, with the 3 most recent studies finding a positive association between cannabis use and willingness to expend effort for reward on the EEfRT (Taylor and Filbey, 2021; Acuff et al., 2022; Vele et al., 2022). Unlike the EEfRT, rewards in the PhEft are food-based and non-probabilistic, which could explain the difference in findings. Nonetheless, although motivation is a multi-faceted concept and additional studies using alternative measures are needed to comprehensively assess the potential link with cannabis use, present and previous evidence suggests that non-acute cannabis use is not associated with lower willingness to expend effort for reward.
"There are only 2 existing studies, to the authors' knowledge, that assess the association between cannabis use and some subjective measure of reward liking (Skumlien et al., 2021b). These showed lower mood responses to positive feedback on a spatial delayed response task (Martin-Soelch et al., 2009) and a lower increase in pleasantness ratings to female compared with male touch in cannabis users compared with controls (Zimmermann et al., 2019). However, their small sample sizes and relatively complex designs limit their ecological validity, and in both cases a significant difference between cannabis users and controls was found for only a few specific statistical comparisons or trial types. The RRPt has the advantage that it provides clear, in-the-moment assessment of responses to several typical rewards. Our results suggest that cannabis use is not associated with reduced subjective wanting or liking of food, money, and music rewards."
https://academic.oup.com/ijnp/article/26/1/9/6674260?login=false [2777]
"People like to get high," note Inzlicht et al in "Chronic Cannabis Use in Everyday Life: Emotional, Motivational, and Self-Regulatory Effects of Frequently Getting High" (2024)...and other phenomenal discoveries quickly followed:
"Getting high was associated with more positive emotions and fewer negative emotions. Contrary to stereotypes, we observed minimal effects on motivation or objective effort willingness. However, getting high was associated with lower scores on facets of conscientiousness. Surprisingly, there was no evidence of a weed hangover. Relative to less frequent users, very frequent users exhibited more negative emotions dispositionally, but they were more motivated. They also reported less self-control and willpower. As attitudes about cannabis are changing, our findings provide a rich description of its chronic use."
Their Figure 4 shows
"Frequency of Cannabis Use, Mode of Use, and Reasons for Use. (A) Participants Were High 64% of the Time; and They Got High by Smoking Cannabis Flower (54%), Vaping Dried Flower or Cannabis Concentrates (22%), or Eating Cannabis Edibles (21%). (B) In Total, Participants Gave 5,847 Reasons for Ingesting Cannabis, Which Comes Out to 2.48 Reasons Per Time They Got High. The Most Frequent Reasons for Use Were Because Participants Liked the Feeling (22%), Because It Helped Them Feel Creative and Perceive Things Differently (17%), to Forget About Worries (17%), and to Help Concentrate (16%)"
https://journals.sagepub.com/doi/10.1177/19485506241245744 [4637]
Liao et al (2019) in a Chinese-Canadian collaboration "Efficacy of omega-3 PUFAs in depression: A meta-analysis" reported:
"We conducted this meta-analysis of double-blind randomized placebo-controlled trials to estimate the efficacy of omega-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), in the improvement of depression. We applied a systematic bibliographic search in PubMed and EMBASE for articles published prior to 20 December 2017. This meta-analysis was performed using RevMan 5.3 and R 3.4.3, and means and standard deviations were calculated in fixed- or random-effects models based on the results of the Q-test. A sensitivity analysis was also conducted to evaluate the stability of the results, and publication bias was evaluated by a funnel plot and Egger's linear regression analysis. Our search resulted in 180 articles; we analyzed 26 studies, which included 2160 participants. The meta-analysis showed an overall beneficial effect of omega-3 polyunsaturated fatty acids on depression symptoms (SMD = -0.28, P = 0.004). Compared with placebo, EPA-pure (=100% EPA) and EPA-major formulations (≥60% EPA) demonstrated clinical benefits with an EPA dosage ≤1 g/d (SMD = -0.50, P = 0.003, and SMD = -1.03, P = 0.03, respectively), whereas DHA-pure and DHA-major formulations did not exhibit such benefits.Current evidence supports the finding that omega-3 PUFAs with EPA ≥ 60% at a dosage of ≤1 g/d would have beneficial effects on depression. Further studies are warranted to examine supplementation with omega-3 PUFAs for specific subgroups of subjects with inflammation, severity of depression, and the dose response for both EPA and DHA supplementation."
https://www.nature.com/articles/s41398-019-0515-5.pdf [3224]
"Xie et al (2021) performed a "Multi-Omics Interpretation of Anti-Aging Mechanisms for ω-3 Fatty Acids":
"Aging is one of the hottest topics in biomedicine. Previous research suggested that ω-3 fatty acids have preventive effects on aging. However, most of previous studies on the anti-aging effects of ω-3 fatty acids are focused on clinical observations, and the anti-aging mechanisms of ω-3 fatty acids have not been fully elucidated. This stimulated our interest to use multi-omics data related to ω-3 fatty acids in order to interpret the anti-aging mechanisms of ω-3 fatty acids. First, we found that ω-3 fatty acids can affect methylation levels and expression levels of genes associated with age-related diseases or pathways in humans. Then, a Mendelian randomization analysis was conducted to determine whether there is a causal relationship between the effect of ω-3 fatty acids on blood lipid levels and variation in the gut microbiome. Our results indicate that the impact of ω-3 fatty acids on aging is partially mediated by the gut microbiome (including Actinobacteria, Bifidobacteria and Streptococcus). In conclusion, this study provides deeper insights into the anti-aging mechanisms of ω-3 fatty acids and supports the dietary supplementation of ω-3 fatty acids in aging prevention."
https://www.mdpi.com/2073-4425/12/11/1691/pdf?version=1635140212 [3223]
Fortunately "Omega-3 Fatty Acids Mitigate Long-Lasting Disruption of the Endocannabinoid System in the Adult Mouse Hippocampus Following Adolescent Binge Drinking" say Serrano et al (2025):
"Adolescent binge drinking has lasting behavioral consequences by disrupting the endocannabinoid system (ECS) and depleting brain omega-3. The natural accumulation of omega-3 fatty acids in cell membranes is crucial for maintaining the membrane structure, supporting interactions with the ECS, and restoring synaptic plasticity and cognition impaired by prenatal ethanol (EtOH) exposure. However, it remains unclear whether omega-3 supplementation can mitigate the long-term effects on the ECS, endocannabinoid-dependent synaptic plasticity, and cognition following adolescent binge drinking. Here, we demonstrated that omega-3 supplementation during EtOH withdrawal increases CB1 receptors in hippocampal presynaptic terminals of male mice, along with the recovery of receptor-stimulated [35S]GTPγS binding to Gαi/o proteins. These changes are associated with long-term potentiation (LTP) at excitatory medial perforant path (MPP) synapses in the dentate gyrus (DG), which depends on anandamide (AEA), transient receptor potential vanilloid 1 (TRPV1), and N-methyl-D-aspartate (NMDA) receptors. Finally, omega-3 intake following binge drinking reduced the time and number of errors required to locate the escape box in the Barnes maze test. Collectively, these findings suggest that omega-3 supplementation restores Barnes maze performance to levels comparable to those of control mice after adolescent binge drinking. This recovery is likely mediated by modulation of the hippocampal ECS, enhancing endocannabinoid-dependent excitatory synaptic plasticity."
https://www.mdpi.com/1422-0067/26/12/5507 [5340]
So to sum up the situation so far: Perutnina produces bad smells. Bad smells reduce hedonic tone. Anhedonia may lead to substance use. Anhedonia is higher in non-cannabis users. Alcohol and/or a low fibre, low-omega-3 diet may lead to dysbiosis, further reducing hedonic tone. Dysregulation of the ECS is rescued by omega-3. Omega-3 promotes longevity. Metabolites of marijuana enhance a preponderance of F. prausnitzii, in contrast to alcohol use. This makes the cannabis user better equipped to cope with his stressful environment, prolongs his healthspan, and lifts his mood, possibly also by avoidance of a range of gastrointestinal conditions.
In females, a preponderance of good bacteria reduces the risk of T1D in the offspring - and even the offspring of the offspring.
Prohibiting something capable of reducing diabetes in the future is a fraud or a crime of some sort. Cui bono? The insulin industry. The metformin industry too. And drug warriors at all levels.
I asked if you thought there was a mechanism by which air pollution could create or exacerbate insulin resistance.
I expect this has got you wondering about inflammasomes.
"Inflammasomes are cytoplasmic inflammatory signaling protein complexes that detect microbial materials, sterile inflammatory insults, and certain host-derived elements. Inflammasomes, once activated, promote caspase-1-mediated maturation and secretion of pro-inflammatory cytokines, interleukin (IL)-1β and IL-18, leading to pyroptosis. Current advances in inflammasome research support their involvement in the development of chronic inflammatory disorders in contrast to their role in regulating innate immunity."
and
"The most widely studied inflammasome with respect to several human disorders is formed by NLRP3. It contains three domains—LRR [leucine rich repeat domain], NACHT [NAIP [NLR family of apoptosis inhibitory proteins], CIITA [Class II MHC transactivator], HET-E [incompatibility locus protein from Podospora anserina] and TP1 [telomerase-associated protein] shared] domain, and PYD [pyrin domain]—to bind ASC [apoptosis-associated speck-like protein containing a CARD [caspase recruitment domain]]. The formation of the NLRP3 inflammasome is extensively studied in macrophages, where it is a two-step process: priming and activation. PAMPs/DAMPs and cytokines induce non-transcriptional priming via post-translational changes (e.g., deubiquitination) and nuclear factor kappa B (NF-κB) activation via TLR4-induced transcriptional priming, leading to higher NLRP3 expression. The phosphorylation of ASC is also mandatory for NLRP3 scaffold formation. Non-transcriptional priming lasts a short (10-30 min) to intermediate time (30 min-1 h), while transcriptional priming lasts longer (>3 h). TLR-mediated MyD88/IL-1 receptor-associated kinase 1 (IRAK1) regulates non-transcriptional NLRP3 priming, where NLRP3 expression does not change but priming is enough to secrete cleaved caspase-1. A second signal is required for the activation step of NLRP3 and the formation of the NLRP3 signaling complex. A variety of "second signals" activate NLRP3, including potassium (K+) efflux, cathepsin release from lysosomal rupture, mitochondrial ROS and DNA, cardiolipin, calcium signaling, Na+, and Cl- efflux, among others). A newly identified NLRP3 binding partner, NEK7 (NIMA-related kinase 7), forms a NLRP3 inflammasome after K+ efflux. Many particulate substances, such as amyloid β (Aβ), silica, alum, monosodium urate, etc., can cause lysosomal destabilization to activate NLRP3 inflammasome. Autophagy and related proteins inhibit the mitochondrial DNA release into cytosol, regulating NLRP3 activation. The dysregulation of the NLRP3 inflammasome is involved in the pathogenesis of a variety of human disorders, and a better understanding of NLRP3 activation would help identify drug targets for NLRP3-related diseases."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7876066/ [2423]
According to Wikipedia:
"NLR family pyrin domain containing 3 (NLRP3) (previously known as NACHT, LRR and PYD domains-containing protein 3 [NALP3] and cryopyrin), is a protein that in humans is encoded by the NLRP3 gene located on the long arm of chromosome 1.
"NLRP3 is expressed predominantly in macrophages and as a component of the inflammasome, detects products of damaged cells such as extracellular ATP and crystalline uric acid. Activated NLRP3 in turn triggers an immune response. Mutations in the NLRP3 gene are associated with a number of organ specific autoimmune diseases."
https://en.wikipedia.org/wiki/NLRP3 [2421]
Using knockout mice, in 2010 Jha et al showed "The Inflammasome Sensor, NLRP3, Regulates CNS Inflammation and Demyelination via Caspase-1 and Interleukin-18"
https://www.jneurosci.org/content/jneuro/30/47/15811.full.pdf [2928]
Grant and Dixit had elaborated in Frontiers in Immunology in 2013 in "Mechanisms of disease: inflammasome activation and the development of type 2 diabetes":
"The NLRP3 Inflammasome Regulates IL-1β Secretion During Metabolic Stress
Given the recent developments in understanding inflammation as a mediator of disease progression, an understanding of factors related to IL-1β regulation is in order. IL-1β is a proinflammatory cytokine that is implicated in the pathogenesis of many inflammatory diseases including diabetes, rheumatoid arthritis and genetic auto-inflammatory disorders (Dinarello, 2011). Although IL-1β is produced by many cell types, it is predominately produced by monocytes, macrophages, and neutrophils (Dinarello, 2011). While most cytokines are regulated at the transcriptional (gene regulation) level, IL-1β is further regulated at the protein level, being stored as an inactive pro-form, which must be cleaved by the IL-1β processing cysteine protease, caspase-1 (Figure 1) for its secretion and activation (Dinarello, 2011). As an additional level of control, caspase-1 is also stored in an inactive state which in turn is activated within large cytosolic multiprotein complexes termed 'inflammasomes' upon receiving specific signals (Schroder and Tschopp, 2010). Classically, the inflammasome driven caspase-1 activation and IL-1β secretion occurs as innate immune cells like macrophages engulf bacterial, fungal, and viral proteins. The inflammasome activation is therefore a vital immune response to protect the host against numerous pathogens (Schroder and Tschopp, 2010). Interestingly, new evidence suggest that inflammasome activation may be important in chronic diseases such as obesity and diabetes where low grade inflammation occurs without overt infection (Schroder and Tschopp, 2010)."
and they say:
"Among the panoply of pro-inflammatory cytokines that are linked to chronic metabolic diseases, new data suggests that interleukin-1β (IL-1β) may play an important role in initiating and sustaining inflammation-induced organ dysfunction in T2D. Therefore, factors that control secretion of bioactive IL-1β have therapeutic implications. In this regard, the identification of multiprotein scaffolding complexes, 'inflammasomes,' has been a great advance in our understanding of this process. The secretion of bioactive IL-1β is predominantly controlled by activation of caspase-1 through assembly of a multiprotein scaffold, 'inflammasome' that is composed of NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3) ASC (apoptosis associated speck-like protein containing a CARD [caspase activation recruitment domain]) and procaspase-1. The NLRP3 inflammasome appears to be an important sensor of metabolic dysregulation and controls obesity-associated insulin resistance and pancreatic beta cell dysfunction."
Their Figure 1 briefly describes the inflammasome process
and
"Reduced NLRP3 Inflammasome Activation Increases Insulin Sensitivity and Improves Glucose Homeostasis
"The NLRP3 inflammasome, as described in Figure 1, has emerged as a key regulator of glucose and insulin homeostasis. Specifically, pre-clinical studies have shown that the genetic deletion of Nlrp3 and Asc in high-fat diet fed mice results in improved glucose tolerance and enhanced insulin sensitivity (Stienstra et al., 2011; Vandanmagsar et al., 2011; Wen et al., 2011). Along with systemic improvements in glucose and insulin homeostasis, the gene knockout animals, i.e., Nlrp3−/− and Asc−/− have decreased circulating IL-18, and reduced adipose tissue IL-1β, markers of caspase-1 activation (Vandanmagsar et al., 2011). The pleiotropic effects of inhibition of NLRP3 inflammasome in obesity are evident by improved insulin signaling in adipose tissue, liver, and skeletal muscle and increased insulin secretion in the pancreas [Figure 2; (Stienstra et al., 2011; Vandanmagsar et al., 2011; Wen et al., 2011)]."
https://www.frontiersin.org/articles/10.3389/fimmu.2013.00050/full [2425]
In Mexico, Garcia-Morales et al further underlined the importance of IL-1β in "CBD Inhibits In Vivo Development of Human Breast Cancer Tumors" (2023), finding prophylactic as well as therapeutic effects:
"Inflammation is a critical component of cancer development. Previously, we showed in vitro that IL-1β treatment of non-invasive human breast cancer MCF-7 cells promoted their transition to a malignant phenotype (6D cells). This epithelial-mesenchymal transition was reverted by exposure to cannabidiol (CBD). We show in a murine model that subcutaneous inoculation of 6D cells induced formation and development of tumors, the cells of which keep traits of malignancy. These processes were interrupted by administration of CBD under two schemes: therapeutic and prophylactic. In the therapeutic scheme, 6D cells inoculated mice developed tumors that reached a mean volume of 540 mm3 at 45 days, while 50% of CBD-treated mice showed gradual resorption of tumors. In the prophylactic scheme, mice were pre-treated for 15 days with CBD before cells inoculation. The tumors formed remained small and were eliminated under continuous CBD treatment in 66% of the animals. Histological and molecular characterization of tumors, from both schemes, revealed that CBD-treated cells decreased the expression of malignancy markers and show traits related with apoptosis. These results confirm that in vivo CBD blocks development of breast cancer tumors formed by cells induced to malignancy by IL-1β, endorsing its therapeutic potential for cancer treatment."
Concerning the prophylaxis, it is one of the Die-Rather-Than-Get-High studies, restricted to CBD alone. THC and the other components of cannabis were ignored.
However, and as you might expect, and importantly for the Defence's central hypothesis that prevention of disease is better than cure, the prophylactic scheme performed better than the therapeutic one:
"The graph in Figure 2A shows that mice pre-treated with CBD for 15 days and then injected with 6D cells developed, in 5 days, tumors that were 50% smaller than those induced in mice not pre-treated with CBD. After 60 days of continuous peritumoral CBD administration, the tumors were reduced to an average volume of only 7.1 mm3, while in CBD-untreated mice the tumors reached an average volume of 223 mm3. Furthermore, under these PS conditions, tumor resorption was observed in 66% of the animals at the end of the experiment (60 days). These results showed that pre-treatment of mice with CBD before inoculation with the 6D cells delays tumor development and favors their resorption."
And here is that graph and the mice in question.
https://www.mdpi.com/1422-0067/24/17/13235 [3025]
For those who prefer getting high to dying though, Safir et al (2025) proclaim the benefits of a THC/CBD/humulene extract:
"From the GC-MS analysis, the following bioactive compounds were found: cannabidiol (CBD), tetrahydrocannabinol (THC), and humulene. The antiproliferative activities of the extract were determined on HeLa cells by using MTT, Crystal Violet, and Trypan Blue assays with an IC50 value suggesting 51%-77.6% lethality. The bioinformatics analysis of molecular docking proved significant ligand-protein interactions of CBD, THC, and humulene with cancer-associated proteins such as PD-1/PD-L1, TNF-α, and MMP-9. In vivo, breast cancer was first established in female Sprague-Dawley rats with 7,12-dimethylbenz(a)anthracene (DMBA) then treated with cannabinoids either singularly or in combination. Detailed treatment demonstrated that the use of the three cannabinoids simultaneously yielded the best anticancer and anti-inflammatory outcomes together with the best tumor reduction. The concentration of serum biomarkers of inflammation and tumor progression was substantially reduced in treated groups compared to the control group, which proves the synergistic effects of these cannabinoids in breast cancer therapy."
https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1546062/full [5231]
Explaining "The molecular anti-metastatic potential of CBD and THC from Lebanese Cannabis via apoptosis induction and alterations in autophagy" Younes et al recall:
"It was demonstrated that THC compounds can halt the progression of breast, brain, leukemia, lung, melanoma, prostate, pancreatic, hepatocellular, and colon cancer in vitro and in vivo. Other studies investigated the anti-cancer properties of CBD in breast, lung, glioma, myeloma, colon and prostate cancer among many others. However, very few studies focused on the combination of cannabinoids on cancer cells. A study conducted by Marcu et al. on glioblastoma, demonstrated that combining CBD with THC may increase the efficacy of treatment via the synergistic inhibition of cell proliferation and the induction of apoptosis. This was similar to the results of a study conducted on melanoma cells exposed to equal amounts of CBD and THC. Another study showed a synergistic effect of CBD and THC on the suppression of leukemic cell growth particularly when combined with chemotherapeutic drugs which might improve patients survival.
"More recently, a study conducted by Schoeman et al., focused on assessing the anticarcinogenic effect of different CBD and THC mixtures on breast cancer. This study provided further evidence on the promising antiproliferative effect of cannabinoids mixtures on breast cancer cells with no cytotoxic effect on normal cells. In fact, breast cancer is one of the most frequent malignancies among women and a leading cause to death worldwide."
https://www.nature.com/articles/s41598-024-76340-x [3741]
In London, Hill et al (2023) used genetically engineered mouse models of LUAD [lung adenosarcoma] to functionally examine whether PM exposure promotes lung tumour development. They report that in the murine lung cancer model Rosa26LSL-tTa/LSL-tdTomato;TetO-EGFRL858R, mice prone to adenomas with various Kras mutations induced by CRISPR-Cas9 mediated HDR [homology-directed repair] alleles (ET mice)...
"In ET mice, PM exposure led to an upregulation of genes known to regulate macrophage recruitment, including those that encode interleukin-1β (IL-1β), GM-CSF, CCL6 and NF-κB and the epithelial-derived alarmin IL-33 (Fig. 3b). AT2 cells are a probable cell of origin of lung adenocarcinoma, and the bleomycin lung injury model has identified a keratin 8-positive (KRT8+) subset of these cells as progenitors that mediate alveolar regeneration driven by inflammatory signals such as IL-1β"
and
"...proposed that lung macrophages, which release inflammatory cytokines when exposed to PM, may be central to tumour promotion. we isolated AT2 cells from et mice not exposed to PM, induced EGFRl858r expression ex vivo and co-cultured the cells with macrophages exposed in vivo to either PM or pbs (fig. 3e). both PM-exposed interstitial macrophages and alveolar macrophages increased the ofe of EGFR mutant AT2 cells (interstitial, p = 0.0095; alveolar, p = 0.0002; fig. 3f). this result indicates that a key mediator of PM-induced inflammation arises from macrophages. previous reports have shown that il-1β, derived from lung macrophages, is required for the formation of KRT8+ AT2 progenitor cells after bleomycin injury. therefore, we reasoned that il-1β may be a key molecular mediator of tumour promotion and the pollutant-driven change in cell state. il-1β was upregulated in PM-treated lungs and predominantly appeared within cd68+ macrophages (extended data fig. 5j,k). furthermore, treatment of EGFR mutant AT2 cells in vitro with il-1β resulted in larger KRT8+spc+ organoids (extended data fig. 5l). finally, to test the requirement of il-1β in PM-enhanced adenocarcinoma formation, we initiated oncogene expression in the doxycycline-inducible ccsp-rtta;teto-EGFRl858r model and exposed mice to PM with concomitant administration of an anti-il-1β or a control antibody (200 μg per dose; extended data fig. 5m). treatment with an anti-il-1β antibody during PM exposure was sufficient to attenuate EGFR-driven LUAD formation (p = 0.034; fig. 3g). collectively, these data establish that PM-exposed macrophages are sufficient to induce a progenitor-like state in EGFR mutant AT2 cells. moreover, macrophages are a key source of il-1β in response to PM and il-1β signalling is required for the promotion of PM-mediated EGFR-driven LUAD."
And here are Figures 5K and 5L
[interleukin 1 beta 3045]
https://lirias.kuleuven.be/bitstream/20.500.12942/721151/2/Lung%20adenocarcinoma%20promotion%20by%20air%20pollutants.pdf [3045]
Now I completely understand if Slovenians want to deprive their fellow citizens of the prophylactic and anti-proliferative benefits of IL-1β. Fewer Slovenians will mean more Slovenia per person, or something. It is not for me to criticise the culture or other people's beliefs. All I can say is I would do anything to prevent breast cancer (in which the female-to-male incidence rate ratio (FMIRRs) was calculated at 122, in an international study by Ly et al in 2012). This would seem to include imaginary "offences" of the ZPPPD.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3553266/ [3024]
"Air pollution is the single largest environmental health risk in Europe and a major cause of premature death and disease. Latest estimates by the European Environment Agency (EEA) show that fine particulate matter (PM2.5) continues to cause the most substantial health impacts."
Both the EEA and WHO say it's the biggest environmental health risk, and
"The EEA estimates that, in 2020, approximately 238,000 premature deaths were attributable to PM2.5 in the 27 EU Member States. In 2020, premature deaths attributed to exposure to fine particulate matter fell by 45% in the EU-27, compared to 2005."
https://www.eea.europa.eu/en/topics/in-depth/air-pollution/eow-it-affects-our-health [2630]
So that's good. However we know Slovenia has a lot of heart disease and cancer, and that you don't necessarily need to be a tobacco smoker or an alcoholic to succumb to these.
"Ambient (outdoor) air pollution is estimated to have caused 4.2 million premature deaths worldwide in 2019.
"Some 89% of those premature deaths occurred in low- and middle-income countries, and the greatest number in the WHO South-East Asia and Western Pacific Regions."
https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health#:~:text=WHO%20estimates%20that%20in%202019,to%20cancer%20within%20the%20respiratory [2631]
According to the IQAir World Air Quality Report, the good news in 2024 is...we beat Bosnia:
Can Ptuj's pong be carcinogenic? Figure 2 of "Cancer Mortality Risks from Long-term Exposure to Ambient Fine Particle" from Wong et al (2016) shows in Hong Kong:
The pattern of association between all-cancer mortality risk and long-term exposure to PM2.5 (μg/m3). Solid line (95% CI: dashed line) based on fully adjusted model in Table 1, with natural spline on 2 degrees of freedom. The marks above the x-axis show the measurements with the crowdedness, indicating the distribution of PM2.5 concentration.
"PM2.5 was associated with all-cancer mortality [HR, 1.22; 95% confidence interval (CI), 1.11-1.34] as well as cause-specific cancer mortality, including all digestive organs (HR, 1.22; 95% CI, 1.05-1.42), upper digestive tract (HR, 1.42; 95% CI, 1.06-1.89), and accessory digestive organs (HR, 1.35; 95% CI, 1.06-1.71). In female, the associations were shown in breast (HR, 1.80; 95% CI, 1.26-2.55) and genital organs (HR, 1.73; 95% CI, 1.17-2.54; Table 2). PM2.5 was not significantly (P > 0.05) associated with external causes. A linear concentration-response relationship between PM2.5 and all-cancer mortality was shown (Fig. 2)."
https://aacrjournals.org/cebp/article/25/5/839/71066/Cancer-Mortality-Risks-from-Long-term-Exposure-to [3875]
Rao et al were also on the case in 2014, here's their diagram from "Air Pollution as a Risk Factor for Type 2 Diabetes" and summarise relevant investigations starting in 1985 up to its publication in 2014.
"Few studies have examined the relationship between incident T2DM and ambient air pollution exposure. Krämer et al. conducted an investigation of the association of incident T2DM with ambient air pollution using data from the Study on the Influence of Air Pollution on Lung, Inflammation and Aging (SALIA) cohort in Germany. Nondiabetic women who were 54-55 years old at baseline (1985-1995) were followed until 2006. Complement factor 3 cleavage product C3c was used as a marker for subclinical inflammation. The authors found that T2DM incidence increased by 15% (95% CI 4-27) per interquartile range of traffic-related PM or by 15% (95% CI 4-27) to 42% (95% CI 16-73) per interquartile range of NO2. Women with high C3c levels were more susceptible to PM-related risk of diabetes than women with low C3c levels (95% CI 1.05-1.18 for an increase in C3c by 10 mg/dL) (Kramer et al., 2010). Andersen et al. followed 51,818 participants of the Danish Diet, Cancer, and Health cohort in the Danish National Diabetes Register from baseline (1993-1997) to 2006. Nitrogen dioxide levels were measured at the residential addresses of the cohort participants. After an average of 9.7 years of follow-up, they detected a positive association between air pollution and confirmed cases of diabetes [hazard ratio (HR) 1.04 (95% CI 1.03-1.08)] per interquartile range of 4.9 µg/m2 mean NO2 levels]. The association was stronger in people who were physically active [HR 1.10 (95% CI 1.03-1.16)] or non-smokers [HR 1.12 (95% CI 1.05-1.20)] suggesting that reductions in ambient air pollution exposures may particularly benefit individuals living healthier lifestyles. In one of the few incident studies of T2DM and ambient air pollution exposure among African-Americans, Coogan et al. followed 3992 women residing in Los Angeles from 1995 to 2005. The authors reported that those who had higher exposure to air pollutants (PM2.5 and NO2) were more likely to develop T2DM. The incidence rate ratio (IRR) for T2DM for a 10 µg/m3 increase in PM2.5 was 1.63 (95% CI 0.78-3.44), and the IRR for NO2 (per 12.4 parts per billion) was 1.14 (95% CI 1.07-1.46) (Coogan et al., 2012)."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306726/ [2426]
Which brings us to "Particulate air pollution exaggerates diet-induced insulin resistance through NLRP3 inflammasome in mice" (2023) by Zhong et al.
The researchers from Wuhan, Shandong, Cleveland, Portland and Yakima say:
"T2D has dramatically increased in developing countries in recent decades. By the year 2030, it is expected that two-thirds of all diabetes cases will occur in low-to middle-income countries, which could not be completely explained by obesity (Hu, 2011). Therefore, there is an urgent need to study the emerging risk factors and mechanisms behind the spike in the incidence of T2D. While a number of factors including genetics, diet, physical activity, smoking, and alcohol use have been extensively studied, the role of factors in the physical environment such as air pollution has been underappreciated. Air pollution, especially particulate matter 2.5 (PM2.5) that is rising at an alarming rate particularly in developing countries, has been linked to insulin resistance and T2D in both human and animal studies (Chen et al., 2016; Brook et al., 2008; Kramer et al., 2010; Sun et al., 2009; Haberzettl et al., 2016). It has been postulated that oxidative stress and inflammation may be involved in the pathophysiology of PM2.5-associated insulin resistance (Sun et al., 2009; Haberzettl et al., 2016; Rao et al., 2018). However, the exact molecular mechanism of how PM2.5 causes insulin resistance remains elusive."
But not for long:
"Priming (first signal) and assembly (second signal) of NLRP3 inflammasome activation were assessed by measuring the transcription of Nlrp3/Il-1β and detecting the activity of caspase-1 and secretion of IL-1β. We found PM2.5 exposure exaggerated insulin resistance and increased IL-1β production in the HFD-fed WT mice, but not Nlrp3−/− mice. Gene expressions of Nlrp3 and Il-1β in the lungs and peritoneal macrophages were upregulated in WT mice exposed to PM2.5. When stimulated with LPS [lipopolysaccharide] (first signal) or monosodium urate (second signal), PM2.5 exposure was able to enhance the activity of caspase-1 and IL-1β secretion, suggesting that PM2.5 may serve as a stimulus of either the first or second signal for NLRP3 inflammasome activation. Effects of PM2.5 on caspase-1 activation and IL-1β secretion were partially blocked in Tlr4Lps-d mice. Reactive oxygen species (ROS), co-localization of NLRP3 and mitochondria, and secondary lysosomes in macrophages were increased after PM2.5 exposure, while deficiency of antioxidant gene Nrf2 in mice significantly enhanced PM2.5-induced secretion of IL-1β. Imaging flow cytometry and transmission electron microscopy demonstrated an engulfment of PM2.5 particles by macrophages, while suppression of phagocytosis by cytochalasin D abolished PM2.5-induced transcription of Nlrp3/Il-1β. Our results demonstrated a critical role of NLRP3 inflammasome in PM2.5 exaggerated insulin resistance, and multiple pathways in the first and second signals of NLRP3 inflammasome activation may be involved."
...and briefly, they conclude:
"We found that PM2.5 results in NLRP3 inflammasome activation, an important risk factor of obesity-induced insulin resistance."
https://www.sciencedirect.com/science/article/abs/pii/S026974912300605X [2420]
Cao et al determined that the "NLRP3 inflammasome activation determines the fibrogenic potential of PM2.5 air pollution particles in the lung" (2021) but
"due to the complexity in PM2.5 compositions, it is difficult to differentiate the roles of the components in triggering this pathway."
https://pubmed.ncbi.nlm.nih.gov/34949371/ [2428]
However it is unlikely they were faced with the range of potential pollutants drifting around in Ptuj on a bad day, with the possibility of synergistic or antagonistic relationships between the 2775 pairs and 67525 triplets of the 75 ingredients of the Town Smell shown. The Court will be interested to hear there are nearly 50 trillion unique combinations of 50 ingredients - 49,765,948,108,474.
[new smell]
https://www.calculatorsoup.com/calculators/discretemathematics/combinations.php [2429]
https://www.calculator.net/exponent-calculator.html [2430]
From "New Insights into the Role of NLRP3 Inflammasome in Pathogenesis and Treatment of Chronic Obstructive Pulmonary Disease" (2021) by Zhang et al at Nantong University, and Hobbs et al in "Genetic loci associated with chronic obstructive pulmonary disease overlap with loci for lung function and pulmonary fibrosis" (2017) we also learned that:
"The most common cause of COPD is smoking, while other factors can also contribute to the onset of this disease, mainly including secondhand smoke, pollution and fumes, age, infections, occupational dusts/chemicals, untreated asthma and genetic factors such as deficiency of alpha-1 antitrypsin. The possible pathogenesis of COPD is strongly linked to chronic inflammatory responses due to the activation of many cell types such as myeloid cells and epithelial cells in response to possible irritants (such as those released from tobacco or polluted air) in the lung of genetically susceptible individuals.
Recently, Hobbs et al identified 22 genetic loci associated with COPD in a large cohort. Among them, 13 represented new associations with COPD, of which 9 (HHIP, CHRNA5, HTR4, FAM13A, RIN3, TGFB2, GSTCD-NPNT, CYP2A6 and IL27-CCDC101) of these 13 loci had previously been associated with measures of lung function in the general population and the remaining 4 (EEFSEC, DSP, MTCL1 and SFTPD) represented new associations with both COPD and lung function, indicating that individual genetic variation explains a small fraction of COPD susceptibility."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5381275/ [2431]
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8405160/ [2432]
And of course we couldn't pass by the opportunity to discover whether consumers of the compulsory Town Smell could affect the NLRP3 by illegally inhaling something voluntarily, and so I am obliged to Suryavanshi et al at the University of Lethbridge, Lethbridge, Alberta and their work "Cannabinoids Alleviate the LPS-Induced Cytokine Storm via Attenuating NLRP3 Inflammasome Signaling and TYK2-Mediated STAT3 Signaling Pathways In Vitro" (2022) who assure me that:
"Our results revealed that CBD and, for the first time, THC significantly inhibited NLRP3 inflammasome activation following LPS + ATP stimulation, leading to a reduction in the levels of IL-1β in THP-1 macrophages [a human monocytic cell line derived from an acute monocytic leukemia patient used to test leukemia cell lines in immunocytochemical analysis of protein-protein interactions, and immunohistochemistry] and HBECs [human bronchial epithelial cells]. CBD attenuated the phosphorylation of nuclear factor-κB (NF-κB), and both cannabinoids inhibited the generation of oxidative stress post-LPS. Our multiplex ELISA data revealed that CBD and THC significantly diminished the levels of IL-6, IL-8, and tumor necrosis factor-α (TNF-α) after LPS treatment in THP-1 macrophages and HBECs. In addition, the phosphorylation of STAT3 was significantly downregulated by CBD and THC in THP-1 macrophages and HBECs, which was in turn attributed to the reduced phosphorylation of tyrosine kinase-2 (TYK2) by CBD and THC after LPS stimulation in these cells. Overall, CBD and THC were found to be effective in alleviating the LPS-induced cytokine storm in human macrophages and primary HBECs, at least via modulation of NLRP3 inflammasome and STAT3 signaling pathways."
https://www.mdpi.com/2073-4409/11/9/1391/pdf?version=1650781025 [2422]
The implications are enormous, as even in 2013, 13 years post-ZPPPD, systemic/peripheral diseases comorbid with depression known to involve IL-1β and the NLRP3 inflammasome included multiple sclerosis, HIV, asthma, and chronic obstructive pulmonary disorders, as evidenced by Table 1 of "The inflammasome: Pathways linking psychological stress, depression, and systemic illnesses" by Iwata et al.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4426992/ [4242]
That same year Puighermanal et al in Barcelona examined the phosphorylation of ribosomal protein S6 kinase p70S6K in mice...
"Different brain areas expressing high levels of CB1R were analyzed 30 min after THC administration (10 mg/kg). Brain tissues were processed for immunoblot analysis to reveal the phosphorylation of the mTOR-dependent site (Thr389) on 70 kDa ribosomal protein S6 kinase (p70S6K(T389)) (Jefferies et al, 1997). All the brain areas analyzed, hippocampus, striatum, cerebellum, frontal cortex, and amygdala, showed an increase in the phosphorylation of p70S6K(T389) after acute THC administration (Figure 1a). As previous studies showed that the subchronic (5 days) treatment with the mTOR inhibitor rapamycin before THC administration prevented the phosphorylation of p70S6K(T389) in hippocampus (Puighermanal et al, 2009), we evaluated the possibility to use a single systemic dose of temsirolimus, a rapamycin analog, to prevent specific effects of THC that could be mediated by the activation of the mTOR pathway. We found that a single administration of temsirolimus, at a dose that did not affect object-recognition memory consolidation on its own (1 mg/kg) (F(5,42)=19.806, n.s. compared to vehicle group; Supplementary Figure S1), was effective at preventing the increase in phosphorylation of p70S6K(T389) promoted by THC (10 mg/kg) administration in the hippocampus and in the amygdala, both regions involved in memory and anxiety-like responses (Figure 1b).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3656376/ [4246]
In 2014 Shao et al at the Department of Pharmacology, Second Military Medical University, Shanghai, China, announced that "Activation of Cannabinoid Receptor 2 Ameliorates DSS-Induced Colitis through Inhibiting NLRP3 Inflammasome in Macrophages" finding that:announced that "Activating Cannabinoid Receptor 2 Alleviates Pathogenesis of Experimental Autoimmune Encephalomyelitis Via Activation of Autophagy and Inhibiting NLRP3 Inflammasome"
https://onlinelibrary.wiley.com/doi/pdfdirect/10.1111/cns.12349 [4244]
That year, proposing that a "syndrome" of modern diet-induced commensal imbalance "caused by the use of antibiotics and changes in diet have caused the chronic disappearance of potentially critical components of the human microbiota", "Role of the Microbiota in Immunity and Inflammation" by Belkaid and Hand at NIH Bethesda, expressed the following beliefs:
"Induction of Regulatory Responses by the Microbiota
Maintenance of tissue homeostasis is imperative for host survival. This fundamental process relies on a complex and coordinated set of innate and adaptive responses that selects and calibrates responses against self, food, commensals, and pathogens in the most appropriate manner. To this end, specialized populations of cells have to integrate local cues such as defined metabolites, cytokines, or hormones, allowing the induction of responses in a way that preserves the physiological and functional requirements of each tissue. As such, the regulatory pathways that are involved in the maintenance of a homeostatic relationship with the microbiota are likely to be tissue specific. However, most of our current understanding of commensal-dependent regulatory pathways relates to the gastrointestinal environment. In the gut, the formidable challenge represented by the exposure to the microbiota, food-derived antigens, metabolites, and pathogens requires a highly complex network of regulatory pathways that is only beginning to be understood (Figure 2). Failure to regulate these responses can lead to severe pathological outcomes ranging from inflammatory bowel diseases (IBD) to allergies or, as further discussed, metabolic syndromes."
https://www.cell.com/fulltext/S0092-8674%2814%2900345-6 [3842]
A further 2014 paper by Johnston et al discusses helminths, which may be missing in many more GI tracts than was previously the case:
"Helminths are remarkably successful parasites: they currently infect more than one quarter of the world's population. It is now well established that the parasites' success is the result of active immunomodulation of their hosts' immune response. Although this primarily secures ongoing survival of the parasites, helminth-induced immunomodulation can also have a number of benefits for the host. Significant reductions in the prevalence of allergy and autoimmune conditions among helminth-infected populations are well recognized and there is now a significant body of evidence to suggest that harmful immune responses to alloantigens may be abrogated as well."
https://journals.lww.com/transplantjournal/Fulltext/2014/01270/Helminths_and_Immunological_Tolerance.4.aspx [3705]
Ke, Shao and others were back in 2016 with "Activation of Cannabinoid Receptor 2 Ameliorates DSS-Induced Colitis through Inhibiting NLRP3 Inflammasome in Macrophages" finding that:
"CB2R activation suppresses NLRP3 inflammasome activation in peritoneal macrophages challenged with LPS/DSS [lipopolysaccharides/ dextran sulphate sodium]"
and
"CB2R activation increases autophagy in peritoneal macrophages challenged with LPS/DSS"
and
"Inducing autophagy mediates the inhibition of CB2R on NLRP3 inflammasome initiation and activation in RAW 264.7 cells [a macrophage cell line that was established from a tumor in a male mouse induced with the Abelson murine leukemia virus] challenged with LPS/DSS"
and
"CB2R activation alleviates but CB2R KO aggravates the symptoms and colon inflammation of DSS-induced colitis mice"
and
"CB2R activation inhibits NLRP3 inflammasome activation and enhances autophagy in colon from DSS-induced colitis mice"
and
"Blockade of autophagy attenuates the protective effect of CB2R activation on DSS-induced colitis"
and
"CB2R activation increases p-AMPK and decreases p-mTOR, p-P70S6K [p70 ribosomal protein S6 Kinase] both in vitro and in vivo"
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0155076 [4245]
14 years after the ZPPPD, Matravadia et al estimated that "Both linoleic and α-linolenic acid prevent insulin resistance but have divergent impacts on skeletal muscle mitochondrial bioenergetics in obese Zucker rats":
"Compared with EPA and DHA, little is known about the relationship between IR and α-linolenic acid (ALA). Although ALA can be endogenously converted into EPA/DHA, tracer studies have revealed that the conversion efficiency is low (<8%). Therefore, it is conceivable that ALA and EPA/DHA have divergent effects on insulin sensitivity, although this remains to be shown. In contrast, n-6 PUFA have traditionally been viewed as detrimental to insulin sensitivity in part because they serve as precursors for the production of proinflammatory eicosanoids; however, this view has been challenged, as accumulating evidence suggests that not all n-6 PUFA are proinflammatory. Interestingly, linolenic acid (LA) may also influence mitochondrial function, as it is the predominant fatty acyl moiety in the mitochondrial-specific phospholipid species cardiolipin. Current estimates suggest that n-6 PUFA are consumed in five- to 20-fold greater amounts than n-3 PUFA; however, the health benefits of LA supplementation remain ambiguous. This highlights the need to study LA and the mechanisms by which it may influence IR in obesity."
https://journals.physiology.org/doi/full/10.1152/ajpendo.00032.2014?rfr_dat=cr_pub++0pubmed&url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&checkFormatAccess=true [3774]
Around the same time, Albert et al (2014) assessed that "Higher omega-3 index is associated with increased insulin sensitivity and more favourable metabolic profile in middle-aged overweight men":
"We assessed whether omega-3 index (red blood cell concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) was associated with insulin sensitivity and other metabolic outcomes in 47 overweight men aged 46.5 ± 5.1 years. Participants were assessed twice, 16 weeks apart. Insulin sensitivity was assessed by the Matsuda method from an oral glucose tolerance test. Linear associations were examined; stratified analyses were carried out with participants separated according to the omega-3 index: lower tertiles (LOI; n = 31) and highest tertile (HOI; n = 16). Increasing omega-3 index was correlated with higher insulin sensitivity (r = 0.23; p = 0.025), higher disposition index (r = 0.20; p = 0.054) and lower CRP concentrations (r = −0.39; p < 0.0001). Insulin sensitivity was 43% higher in HOI than in LOI men (Matsuda index 6.83 vs 4.78; p = 0.009). Similarly, HOI men had disposition index that was 70% higher (p = 0.013) and fasting insulin concentrations 25% lower (p = 0.038). HOI men displayed lower nocturnal systolic blood pressure (−6.0 mmHg; p = 0.025) and greater systolic blood pressure dip (14.7 vs 10.8%; p = 0.039). Men in the HOI group also had lower concentrations of CRP (41% lower; p = 0.033) and free fatty acids (21% lower, p = 0.024). In conclusion, higher omega-3 index is associated with increased insulin sensitivity and a more favourable metabolic profile in middle-aged overweight men."
Their approach attempted to make sense of the mixed findings at that stage:
"There is increasing evidence suggesting that dietary omega-3 polyunsaturated fatty acids (n-3 PUFA), particularly the long-chain fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in marine oils, may improve insulin sensitivity or reduce the incidence of type 2 diabetes. Epidemiological studies have linked higher dietary or plasma n-3 PUFA concentrations with lower risk of diabetes. Rodent studies have also shown that insulin resistance can be reversed by supplementation with fish oil. However, human intervention trials have yielded inconclusive results. In a systematic review that included 11 randomized controlled trials and 618 participants, n-3 PUFA supplementation did not influence insulin sensitivity. However, the individual trials were highly heterogeneous, including participants with and without type 2 diabetes, utilising a wide range of n-3 PUFA doses, as well as adopting a range of treatment and control oils. In association with weight loss or caloric restriction supplementation with fish or fish oil increased insulin sensitivity. A study showed that switching to a Mediterranean diet (which includes a lower dietary n-6:n-3 ratio) also increased insulin sensitivity, but it was not possible to isolate the specific effect of n-3 PUFA due to the complexity of dietary interventions. In a simple dietary intervention trial of 12 healthy older adults, changing from non-oily fish to oily fish improved insulin sensitivity. However, in the multicentre KANWU study, addition of fish oil to a high saturated fat or high monounsaturated fat diet did not influence insulin sensitivity."
https://www.nature.com/articles/srep06697 [3836]
Brown (2016) examines "The Roles of Linoleic and Alpha-linolenic Acid, Their Oxylipins and the PPAR Alpha-, Delta- and Gamma-Related Peroxisomal Pathways on Obesity in the Context of a 'Western' Diet", i.e. how n-6 makes you fat and n-3 doesn't, including:
"Obesity is signalled for by oxidative stress including through LA oxylipin and AGE [Advanced glycation end product, a non-enzymatic covalently bound sugar to
protein or lipid] activation of obesogenic pathways; oxidised products are delivered to adipose tissue likely in significant part by LDL, thereby including oxidised cholesterol, LA oxylipins and wider oxidised products attached to LDL. In a pre-agricultural world oxidative stress levels at the vascular adipose cell interface will mirror the rising availability of seasonal products that are oxidation prone, namely sugars including glucose and fructose, and polyunsaturated fats found in plant reproductive-related material, which together form the basis for a wide range of obesogenic bioactive oxidised products, including oxylipins and AGEs"
[linoleic acid in us body fat 3837]
https://www.researchgate.net/profile/Robert-Brown-82/publication/308193954_The_Roles_of_Linoleic_and_Alpha-linolenic_Acid_Their_Oxylipins_and_the_PPAR_Alpha-_Delta-_and_Gamma-Related_Peroxisomal_Pathways_on_Obesity_in_the_Context_of_a_Western_Diet/links/5d9377d9299bf10cff1f1701/The-Roles-of-Linoleic-and-Alpha-linolenic-Acid-Their-Oxylipins-and-the-PPAR-Alpha-Delta-and-Gamma-Related-Peroxisomal-Pathways-on-Obesity-in-the-Context-of-a-Western-Diet.pdf?_tp=eyJjb250ZXh0Ijp7ImZpcnN0UGFnZSI6InB1YmxpY2F0aW9uIiwicGFnZSI6InB1YmxpY2F0aW9uIn19 [3837]
In a systematic literature review of studies of (mostly) buttocks Guyenet and Carlson (2015) expanded on this observation, which they attribute to seed oils:
"Our results indicate that adipose tissue LA has increased by 136% over the last half century and that this increase is highly correlated with an increase in dietary LA intake over the same period of time."
https://www.sciencedirect.com/science/article/pii/S216183132300114X?via%3Dihub [3838]
Supporters of the Town Smell will be disappointed to learn that, as reported in 2021, researchers in "more than 50 clinical studies are currently underway to elucidate the role of NLRP3.
"NLRP3 has been considered the gold standard of inflammasome signaling, as many NLRP3 inhibitors are under investigation in clinical trials for coronary artery disease and gout."
21 years after the ZPPPD the NLRP3-lowering properties of THC had expanded...
"An enormous amount of data shows that NLRP3 is involved in the pathophysiology of Alzheimer's, stroke and cardiovascular diseases, asthma, gout, IBD, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, multiple sclerosis, rheumatoid arthritis, myelodysplastic syndrome, obesity-induced inflammation or insulin resistance, type-1 diabetes, oxalate-induced nephropathy, graft-versus-host disease, and silicosis."
and that
"In type-2 diabetes patients, NLRP3 inflammasome activation is higher in myeloid cells, and NLRP3 inflammasome inhibitors might be clinically useful in treating ischemic stroke concomitant with diabetes. The activation of NLRP3 is involved in renal disorders, such as chronic kidney disease (CKD), diabetic nephropathy (DN), and acute kidney injury (AKI), by both canonical and non-canonical pathways. The NLR family (NLRP1, NLRP3, NLRC4, NLRP6, and NLRP12) and their binding partners have mixed roles in the pathogenesis of a variety of cancers."
Finally the friends of prohibition and enemies of weed and all that jazz will be saddened to learn that
"Additionally, α-synuclein itself can activate the NLRP3 inflammasome, raising cytokine levels in PD patients." [2423]
That - and there's much more there about the inflammasome and its components - comes from "Cannabinoids as Key Regulators of Inflammasome Signaling: A Current Perspective" (2020) [2423 - link above].
Xing et al (2023) look at a three-way relationship between atrial fibrillation, the NLRP3 inflammasome and gut microbiota, concluding:
"Activation of the NLRP3 inflammasome and dysregulation of intestinal microecology is a potential target factor that may provide new therapeutic avenues for AF. The interactions between NLRP3 inflammasome and intestinal microecological metabolic processes have been gradually elucidated, both of which affect the developmental process of AF, and whether there is a synergistic or causal relationship needs the further investigation. Gut microbial dysbiosis may promote increased AF susceptibility or AF substrates by influencing their derivatives and metabolites to modulate oxidative stress responses, regulate metabolism, and upregulate NLRP3 inflammasome expression, leading to cardiac inflammatory responses, myocardial fibrosis, or metabolic disturbances. In this review, less high-quality direct evidence demonstrated a relationship between the gut microbiota-AF-NLRP3 inflammasome axis. Only SCFA and LPS have been shown to be directly associated with the NLRP3 inflammasome and AF. TMAO [trimethylamine oxide], BAs [bile acids] and IS [indoxyl sulphate] although all shown to be associated with NLRP3 inflammasome activation and AF, respectively, have not yet been found to be directly associated with all three. This review collates existing studies on gut microbiota derivatives and metabolites and immune response and AF occurrence, with a view to providing a reference for in-depth research in this area.
"More valuable researches should inspire the development of new theoretical and drug targets in AF."
The authors state in the study how metabolites, particularly short chain fatty acids and lipopolysaccharides created during dysbiosis in the gut, may create oxidative stress and trigger the upregulation of NLRP3 in inflammation. This may lead to inflammatory responses in the heart, which may then contribute to the pathogenesis of atrial fibrillation.
Their Figure 4 illustrates these pathways
"The levels of NLRP3 inflammasome, IL-1β, and IL-18 were upregulated in IS-treated cardiomyocytes, leading to cardiomyocyte apoptosis; BAs are a class of DAMPs [damage-/hazard-associated molecular patterns] that activate the NLRP3 inflammasome in a calcium influx dependent manner; LPS is involved in the typical and atypical activation of NLRP3 inflammasome. The sharp increase in circulating LPS level is associated with the up-regulation of NLRP3 inflammasome expression in rats, which increases their susceptibility to AF. SCFA is a potential contributor to the pathogenesis of AF. SCFAs promote the improvement of intestinal barrier function. Low SCFA levels lead to decreased intestinal integrity and promote the entry of substances such as LPS into blood and tissues. SCFA supplementation can prevent the up-regulation of phosphorylation of CAMK II [calmodulin-dependent kinase II] and RyR2 [ryanodine receptor 2], and prevent disordered fibrosis, collagen expression, and NLRP3 inflammasome activation in atrial tissue. TMAO may be involved in the activation of the p65 NF-κB signaling pathway by activating NLRP3. Metabolites of gut microbiota can induce inflammation, myocardial fibrosis, autonomic remodeling, electrical remodeling, and other pathological processes of AF by directly or indirectly activating NLRP3 inflammasome."
https://www.frontiersin.org/articles/10.3389/fimmu.2023.1273524/full [4236]
According to "Microbiome and Heart Failure: A Comprehensive Review of Gut Health and Microbiota-Derived Metabolites in Heart Failure Progression" from Orjichukwu et al (2025):
"From the mechanistic stand-point, decreased availability of SCFAs has been demonstrated to further the progression of HF through multiple mechanisms. Lower levels of butyrate and acetate reduce intestinal barrier integrity, thus increasing intestinal permeability and endotoxin acting as lipopolysaccharides (LPS) to enter the circulation and elicit a systemic inflammatory response and myocardial damage. Additionally, SCFA deficiency decreases G-protein-coupled receptors (GPR41 and GPR43) activation pathways affecting immune modulation and increases pro-inflammatory cytokines including TNF-α and IL-6, both of which have strong links to adverse cardiac remodelling and systolic dysfunction. Furthermore, low levels of SCFA decrease energy availability to colonocytes and the failing myocardium contributing to mitochondrial damage, oxidative stress, and contractility dysfunction. Overall, these mechanisms collectively show how low levels of SCFAs may directly promote pathophysiological mechanisms that can worsen outcomes in HF.
"The role of SCFAs in the context of heart failure presents an intriguing area of inquiry (see Figure 2). These compounds are synthesized from dietary fiber through the fermentation processes conducted by gut microbiota. SCFAs serve a vital function by providing energy to enterocytes and various innate immune cells. However, their influence extends beyond mere energy provision; they engage with endothelial cells and immune cells through signaling mechanisms mediated by G-protein-coupled receptors (GPRs). This interaction leads to the repression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), which occurs in conjunction with histone deacetylases (HDACs). Consequently, SCFAs inhibit the expression of Bcl-2 interacting protein 3 (BNIP3), thereby mitigating the production of pro-inflammatory cytokines. These cytokines are known contributors to cardiac and vascular damage, which can result in pressure overload, ischemic injury, and ultimately, heart failure. In this complex interplay, components such as tumor necrosis factor alpha (TNF-α), NO, and adenosine triphosphate (ATP) are also implicated, further underscoring the multifaceted role of SCFAs in cardiovascular health. Although the mechanisms are intricate, the implications of SCFAs in modulating inflammation and cellular responses remain a pivotal aspect of understanding heart failure pathology."
https://www.mdpi.com/2076-3271/13/4/302 [5822]
What does this have to do with Covid?
One of the common cardio complications after a Covid infection is atrial fibrillation.
It is to be noted that there is an upregulation of NLRP3 during SARS2 infection, as well as dysbiosis in the gut since studies are starting to show that the gut is a possible reservoir in Covid.
The mechanisms mentioned in this review may shed some light as to the onset of AF in some patients. It may partly explain the lower Covid mortality rate in cannabis users.
"Pro-inflammatory NLRP-3 signaling activates cytokines, thus generating mitochondrion related inflammatory cascades. This is particularly concerning in elderly patients, who experience an increase in the NLRP-3 inflammasome with age. This exacerbates SARS-CoV-2 infection."
https://www.mdpi.com/1422-0067/24/9/8034/pdf?version=1683528911 [4570]
But there is still a strong faction who would rather (we) die than get high. Besides the newly-discovered property of the 12000-year old medicine THC in attenuating NLRP3, many papers have focussed studiously on CBD, for those who want to attenuate NLRP3 in a half-assed sort of way, and who refuse to have a laugh at the stupid government, deadly prohibitionists, and the hostage doctors at the same time.
For instance "Anti-inflammatory effects of CBD in human microglial cells latently and actively infected with HIV-1 virus" insists on demonstrating "that CBD which is antiinflammatory which does not cause psychotropic effects compared to THC will be of therapeutic significance against HIV-1 infections" even though it admits that "Δ (9)-THC has a high binding affinity in nanomolar (nM) order for cannabinoid receptors 1 and 2 (CB1R = 25.1; CB2R = 35.2 nM), the CBD has 80 fold lower binding affinity to them".
In a classic example of making a discovery and ignoring it because it is not the discovery you want to make, Yndart et al's own chart shows higher THC doses are more effective (and their 2022 paper doesn't even examine THC and CBD combined). But they are resolute that curing AIDS must not be any fun as it is more illegal (or equally illegal, depending on your location).
https://assets.researchsquare.com/files/rs-2142479/v1/b11301ba-ea1d-4a71-a84f-d4f9b8d268af.pdf?c=1666634085 [2424]
Leonard and Aricioglu (2023) in "Cannabinoids and neuroinflammation: Therapeutic implications" exemplify the twisted logic of a pharmaceutical salesperson:
"Since the discovery of the endocannabinoid system and the role that neuroinflammation plays in neurological and psychiatric illness, the potential therapeutic importance of this system has been of growing interest. In addition, the need to develop drugs which specifically target the CB1 and CB2 receptors has been stimulated by the pharmacological complexity of both THC and CBD. This review briefly summarizes the therapeutic potential of the naturally occurring and the synthetic cannabinoids which will need to be developed, if such drugs are to fulfill the therapeutic promise which the cannabinoids offer."
Before going on to remind us:
"The anti-inflammatory effects of cannabinoids are thought to be due specifically to their potential inhibitory effect on NLRP3. In addition, recent findings suggest that cannabinoids, being CB1 receptor agonists, play a key role in this anti-inflammatory mechanism of action. In addition, cannabinoids play a role in inflammatory cytokine signaling pathways, and while our understanding of the molecular mechanisms whereby cannabinoids modulate inflammatory signals is still limited, there is support for the view that they may be therapeutic targets in the regulation of inflammatory signaling mechanisms (Fig. 3)."
https://www.sciencedirect.com/science/article/pii/S2666915323000021 [4243]
Maayah et al (2022) ignored THC from the get-go and decided to
"examine the effect of CBD on cytokine storm-induced cardiac and renal injury using the lipopolysaccharide (LPS)-induced sepsis mouse model."
and found
"...CBD improves cardiac function and reduces renal injury in a mouse model of cytokine storm. Moreover, our data indicate that CBD significantly reduces systemic and renal inflammation to contribute to the improvements observed in a cytokine storm-model of cardiac and renal injury. Conclusions: Overall, the findings of this study suggest that CBD could be repurposed to reduce morbidity in patients with cytokine storm particularly in severe infections such as sepsis."
https://pubmed.ncbi.nlm.nih.gov/36594988/ [3001]
Further examination of the targeting of the ECS in sepsis can be found in "Exploring the versatile roles of the endocannabinoid system and phytocannabinoids in modulating bacterial infections" by Barker and Ferraro (2024)
https://journals.asm.org/doi/10.1128/iai.00020-24 [4675]
The Court is unlikely to reach a conclusion as to how 50 trillion combinations of Ptuj Town Smell components affect the residents' inflammasomes. We can surely assume occupants of more fortunate locations have nothing to fear. No health worries are associated with clean air. "Caspase-1 cleaves Bid to release mitochondrial SMAC and drive secondary necrosis in the absence of GSDMD" (2020) sheds some more detail on the critical role of caspase-1:
"Canonical inflammasomes trigger a rapid secondary necrosis in the absence of GSDMD [gasdermin-D] The canonical and noncanonical inflammasome pathways converge on the caspase-dependent cleavage and activation of the pyroptosis executor GSDMD (Kayagaki et al, 2015; Shi et al, 2015). However, although GSDMD is essential for lytic cell death (pyroptosis) after LPS-induced noncanonical inflammasome activation (Fig S1A), Gsdmd deficiency only delays cell lysis after engagement of canonical inflammasome receptors, such as AIM2 [interferon-inducible protein AIM2 aka absent in melanoma 2] (Figs 1A and S1B-D), NLRC4, and NLRP3 (Figs 1A and S1B-D) (Kayagaki et al, 2015). The absence of caspase-1 and caspase-11 in primary BMDMs [bone-marrow-derived macrophage cells are lab-generated from mammalian bone marrow cells], by contrast, showed a much stronger reduction in lactate dehydrogenase (LDH) release and propidium iodide (PI) influx, and Asc deficiency completely abrogated cell lysis after AIM2 or NLRP3 activation, in line with the reported Apoptosis-associated specklike protein containing a CARD (ASC)-dependent activation of apoptosis in absence of caspase-1 (Pierini et al, 2012; Man et al, 2013; Sagulenko et al, 2013; Chen et al, 2015; Vajjhala et al, 2015)."
https://www.life-science-alliance.org/content/lsa/3/6/e202000735.full.pdf [2468]
https://rupress.org/jem/article-pdf/215/3/827/1170159/jem_20172222.pdf [2469]
"Inflammatory caspases are innate immune receptors for intracellular LPS" say Shi et al in Beijing.
"The murine caspase-11 non-canonical inflammasome responds to various bacterial infections. Caspase-11 activation-induced pyroptosis, in response to cytoplasmic lipopolysaccharide (LPS), is critical for endotoxic shock in mice. The mechanism underlying cytosolic LPS sensing and the responsible pattern recognition receptor are unknown. Here we show that human monocytes, epithelial cells and keratinocytes undergo necrosis upon cytoplasmic delivery of LPS. LPS-induced cytotoxicity was mediated by human caspase-4 that could functionally complement murine caspase-11. Human caspase-4 and the mouse homologue caspase-11 (hereafter referred to as caspase-4/11) and also human caspase-5, directly bound to LPS and lipid A with high specificity and affinity."
https://pubmed.ncbi.nlm.nih.gov/25119034/ [3092]
In fact cannabis prohibition affects decision-making. Falkenstein et al (2024) , a team from Sorbonne and Bonn Universities, measured the "Impact of the gut microbiome composition on social decision-making":
"There is increasing evidence for the role of the gut microbiome in the regulation of socio-affective behavior in animals and clinical conditions. However, whether and how the composition of the gut microbiome may influence social decision-making in health remains unknown. Here, we tested the causal effects of a 7-week synbiotic (vs. placebo) dietary intervention on altruistic social punishment behavior in an ultimatum game. Results showed that the intervention increased participants' willingness to forgo a monetary payoff when treated unfairly. This change in social decision-making was related to changes in fasting-state serum levels of the dopamine-precursor tyrosine proposing a potential mechanistic link along the gut-microbiota-brain-behavior axis. These results improve our understanding of the bidirectional role body-brain interactions play in social decision-making and why humans at times act "irrationally" according to standard economic theory."
About this game:
"Social decision-making refers to processes in which individuals make choices within a social context, meaning that their decisions have consequences for both the individual and others. A large body of evidence shows that social decisions are not influenced solely by self-interest but also by social norms such as fairness considerations. For example, the concept of altruistic punishment describes forgoing personal interest to penalize behavior that is not in line with social norms.
Altruistic punishment is typically studied in the ultimatum game (UG) a classic task from behavioral economics in which humans often reject monetary payoffs when receiving an unfair offer. In more detail, one participant (the proposer) is endowed with a specific amount of money (e.g. €10) and offers a share of the money to a second participant (the responder), who can either accept or reject the offer. If the responder rejects the offer, neither participant receives any money. When participants play this game only once and with an anonymous other participant, it should be their economically rational choice to accept any offer greater than €0. However, many studies show that offers greater than €0 but perceived as unfair (such as €1 or €2 out of €10) are typically rejected reflecting altruistic punishment. Here, we tested whether the behavior of responders in the UG was altered by a 7-week synbiotic intervention."
Those receiving the pro- and pre-biotic supplement were more altrustic.
"Participants in the treatment group rejected a higher proportion of offers after the intake of the synbiotic treatment, thus showing an increased tendency for altruistic punishments (see Fig. Fig.1C1C and D and Table S3, model 1). These results were robust when controlling for age and body mass index (BMI; see Table S3, model 2), and for age and metabolic health (see Table S3, model 3)."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11093127/ [3131]
The Opium Convention plenipotentiaries would have been unable to envision Gong et al's Figure 2: The Overall Landscape of the Pleiotropic Associations Across 4 Gastrointestinal Tract Diseases and 6 Psychiatric Disorders:
"A circular dendrogram included 4 gastrointestinal tract diseases (inner circle, including gastroesophageal reflux disease [GERD], inflammatory bowel disease [IBD], irritable bowel syndrome [IBS], and peptic ulcers disease [PUD]) and 6 psychiatric disorders (second circle; attention-deficit/hyperactivity disorder [ADHD], anorexia nervosa [AN], bipolar disorder [BIP], major depressive disorder [MDD], posttraumatic stress disorder [PTSD], and schizophrenia [SCZ]), resulting in 24 trait pairs. A total of 83 pleiotropic loci were identified across 19 trait pairs (third circle; no pleiotropic loci were identified for IBS-PTSD, PUD-MDD, and PUD-PTSD), in which 53 of 83 top single nucleotide variations (SNVs) showed concordant associations (marked by a plus sign) with a certain pair of traits while the remaining top SNVs showed discordant associations (marked by a minus sign); 24 pleiotropic loci were colocalized for pairwise traits (orange dots, posterior probability of H4 [PP.H4]>0.7); and 11 were colocalized for certain gastrointestinal tract diseases, psychiatric disorders, and gut microorganisms (gray dots, PP>0.7, with the specific microorganism annotated on the lines). A total of 196 significant pleiotropic genes (158 unique) were further identified by multimarker analysis of GenoMic annotation (MAGMA). For the trait pairs with more than 3 pleiotropic genes, we only showed the top 3 pleiotropic genes according to the prioritization of candidate pleiotropic genes, which were shown with the statistical prioritization attenuation manifested by clockwise direction (fourth circle), the genes with the tissue specificity in at least one of gastrointestinal tract or brain tissues and in other tissues identified by E-MAGMA were also highlighted (dark blue dots). Detailed information for 83 pleiotropic loci (eTable 6 in Supplement 1), colocalization results (Table 2), multitrait colocalization results (eTable 17 Supplement 1), significant pleiotropic genes with annotations of tissue specificity (eTable 15 in Supplement 1) was also provided."
...
"Results Extensive genetic correlations and genetic overlaps were found among 22 of 24 trait pairs. Pleiotropic analysis under a composite null hypothesis identified 2910 significant potential pleiotropic SNVs in 19 trait pairs, with 83 pleiotropic loci and 24 colocalized loci detected. Gene-based analysis found 158 unique candidate pleiotropic genes, which were highly enriched in certain GBA-related phenotypes and tissues, whereas pathway enrichment analysis further highlighted biological pathways primarily involving cell adhesion, synaptic structure and function, and immune cell differentiation. Several identified pleiotropic loci also shared causal variants with gut microbiomes. Mendelian randomization analysis further illustrated vertical pleiotropy across 8 pairwise traits. Notably, many pleiotropic loci were identified for multiple pairwise traits, such as 1q32.1 (INAVA), 19q13.33 (FUT2), 11q23.2 (NCAM1), and 1p32.3 (LRP8)."
https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2801422 [5241]
General Smuts would not have envisaged that today's white man would be consuming a credit card's worth of plastic every week, as reported in "Effects of Microplastic Exposure on Human Digestive, Reproductive, and Respiratory Health: A Rapid Systematic Review" and so he might not have appreciated the countervailing effects of cannabinoids, the need for which has certainly increased since 1925. In the studies evaluated by Chartres et al (2024):
"Cytokines such as tumor necrosis factor-α (TNF-α), IL-2, IL-6, IL-5, IL-9, IL-10, IP-10, G-CSF, iLb, Rantes, and IL-1α were measured in multiple studies. TNF-α levels significantly increased in the colon and the intestine. In two studies, TNF-α levels were not significantly different regardless of the exposed group in colon and small intestine. The level of IL-6 also significantly increased in the colon and all or part of the small intestine. The level of IL-10 (anti-inflammatory cytokine) significantly decreased in the colon but not in intestinal serum. There was no significant change in Ilb in the intestine in one study. IL-1α levels significantly increased in the intestine in two studies. For one study, there are two proteins related to inflammation (iNOS and COX-2) with levels that were significantly increased in the exposure group compared to the control. Eight other cytokines were measured in specific studies, and most of them had significant changes (increase or decrease, depending on the specific cytokine) between control and exposure groups."
and
"Across the outcomes, we identified that exposure to microplastics is 'suspected' to be a digestive hazard to humans, including a suspected link to colon cancer, using the key characteristics of carcinogens approach."
and note that
"...plastic production is projected to triple by 2060."
https://t.co/pSMxcnpIQ8 [3870]
By 2026 researchers were running out of excuses to not declare cannabis treatment for IBS a slam-dunk. In "Efficacy of Exogenous Cannabinoids in Pre-Clinical Models of Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis" (2026) from Wang et al:
"Twenty-seven pre-clinical studies involving 408 animals were included. Compared with controls, exogenous cannabinoids significantly reduced disease activity index (SMD = -3.43; 95% confidence interval [CI]: -4.98 to -1.89; I2 = 83%) and histopathological score (SMD = -4.46; 95% CI: -6.37 to -2.54; I2 = 84%). It also decreased levels of myeloperoxidase (MPO), TNF-α, IL-6, and IL-1β. However, substantial heterogeneity was noted across several outcomes."
SMD (Standardized Mean Difference): This measures the "effect size." In statistics, an effect size above 0.8 is "large." An SMD of -3.43 and -4.46 is considered massive. These numbers suggest that the animals given cannabinoids were significantly healthier and had much less tissue damage than the control groups.
95% Confidence Interval (CI): This tells us the range where the true effect likely lies. Because the entire range (e.g., -4.98 to -1.89) is well below zero, we can be highly confident the result wasn't just a fluke of the data.
MPO (myeloperoxidase) is an enzyme that shows how many white blood cells (neutrophils) are attacking the colon.
https://pubmed.ncbi.nlm.nih.gov/41804536/ [6005]
The discovery and understanding of myeloperoxidase (MPO)—the enzyme responsible for the green color of pus and a primary weapon of our immune system—is a journey from "mysterious green pigment" to a cornerstone of cardiovascular and inflammatory medicine.
In the mid-19th century, scientists noticed that purulent discharge (pus) often had a distinct greenish hue.
In 1844 German physician Rudolf Virchow and others identified this "green pigment" within white blood cells.
In 1868 Friedrich Miescher (who also discovered DNA) isolated a substance from the nuclei of white blood cells which he called "nuclein," but he also noted the persistent green protein in his samples.
The modern era of MPO research began during WWII, led by Swedish biochemist Kjell Agner. In 1941 Agner successfully isolated and crystallized the enzyme from dog pus and human empyema (fluid from the lungs). He originally named it Verdoperoxidase (from the Latin viridis for green).
Agner proved that this enzyme wasn't just a pigment; it was a powerful peroxidase containing iron (heme) that could catalyze oxidative reactions.
1960s – 1970s: The Killing Mechanism
Researchers began to realize that MPO was the "ammunition" inside the granules of neutrophils (white blood cells).
1966: Seymour Klebanoff discovered the MPO-H2O2-Halide system. He showed that MPO uses hydrogen peroxide to turn chloride ions into hypochlorous acid (HOCl) - the active ingredient in household bleach. This established MPO as the primary mechanism by which our bodies dissolve bacteria and fungi.
As biotechnology advanced, scientists mapped the enzyme's structure. In 1985 the human MPO gene was cloned. Researchers found that MPO is a "dimer" — two identical halves linked together. This unique structure allows it to withstand the highly oxidative environment it creates.
In the last 30 years, the focus shifted from how MPO kills germs to how it accidentally kills us via chronic inflammation. Researchers found that MPO doesn't just stay inside neutrophils; it leaks into the bloodstream and attaches to blood vessel walls.
Starting in 1994 it was discovered that MPO oxidizes LDL (the "bad" cholesterol), turning it into a "super-toxic" form that creates arterial plaque. MPO was not just found in circulating blood, but was specifically concentrated inside human atherosclerotic lesions (plaque). In "3-Chlorotyrosine, a specific marker of myeloperoxidase-catalyzed oxidation, is markedly elevated in low density lipoprotein isolated from human atherosclerotic intima" MPO's chemical fingerprint was present in the very spots where arteries were narrowing, ending the idea that MPO was responsible only for killing bacteria.
https://pmc.ncbi.nlm.nih.gov/articles/PMC296328/ [6006]
https://pmc.ncbi.nlm.nih.gov/articles/PMC508036/ [6007]
Today, MPO levels are used in hospitals as a predictive marker for heart attacks and a key marker for inflammatory disease activity.
Timeline Summary
1844: Observation of "green pigment" in pus.
1941: Kjell Agner isolates the enzyme (Verdoperoxidase).
1966: Discovery of the "Bleach" killing mechanism (Klebanoff).
1985: Cloning of the human MPO gene.
2000s: Establishment of MPO as a major biomarker for heart disease and chronic inflammation.
2020: Drunk burglar living in Ptuj park attacks global MPO reduction.
2026: A Slovenian court hears about cannabis and myeloperoxidase for the first time - and lets a foreigner pay for them to do it!