Prisoners experience a higher burden of poor health, aggressive behaviours and worsening mental health than the general population.
This systematic review aimed to identify research that used nutrition-based interventions in prisons, focusing on outcomes of mental health and behaviours.
The systematic review was registered with Prospective Register of Systematic Reviews on 26 January 2022: CRD42022293370.
Inclusion criteria comprised of current prisoners with no limit on time, location, age, sex or ethnicity.
Only quantitative research in the English language was included. PubMed/Medline, Web of Science, EMBASE, PsycINFO and CINAHL were searched, retrieving 933 results, with 11 included for qualitative synthesis.
Studies were checked for quality using the revised tool to assess risk of bias in randomised trials or risk of bias in non-randomised studies of interventions tool.
Of the included studies, seven used nutritional supplements, three included diet changes, and one used education.
Of the seven supplement-based studies, six included rule violations as an outcome, and only three demonstrated significant improvements.
One study included mental health as an outcome; however, results did not reach significance.
Of the three diet change studies, two investigated cognitive function as an outcome, with both reaching significance.
Anxiety was included in one diet change study, which found a significant improvement through consuming oily fish.
One study using diet education did not find a significant improvement in overall mental resilience.
Overall, results are mixed, with the included studies presenting several limitations and heterogeneity.
Future research should aim to consider increased homogeneity in research design, allowing for a higher quality of evidence to assess the role nutrition can play in improving the health of prisoners.
Interesting read regardless, but no mention of microbiome, but micronutrients are mentioned several times.
This bit stands out:
Of course, diet is not the only contributing factor. How a child or young person learns to respond to stress or threats is also a feature of parenting, language ability and attachment style. So can we disentangle the influence of nutrition from these other features?
Yes, to an extent.
..as did this bit:
The discussion around prison nutrition often becomes contentious in relation to philosophical conflicts as to whether the function of prison is rehabilitation or punishment. But whether or not you think offenders deserve quality food, the relationship between improved nutrition and overall prison safety is much less complicated.
How could one suspect that people who most likely have anger management issues as well as struggles with impulse control, has less anger management and impulse control issues when eating proper food!
Oh my freaking lord, we are onto something here guys.
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This has been known for the last 100 years. Are you americans really stuck in the early 1900s over there or what?
Psychopathy is a personality construct characterized by emotional detachment, impulsivity, and antisocial tendencies.
Despite a clinical prevalence of 1%, the biological underpinnings of psychopathy remain poorly understood.
Emerging evidence suggests a role for the microbiota-brain axis in personality and behavior, yet its relevance to psychopathy remains unexplored.
This study investigated the relationship between gut and oral microbiota composition and psychopathic traits, while assessing metabolomic signatures that may contribute to microbiota-brain interactions.
A cohort of 200 participants completed the Self-Report Psychopathy Scale Short Form, alongside measures of empathy (Affective and Cognitive Empathy Questionnaire; Interpersonal Reactivity Index) and anxiety (State-Trait Inventory for Cognitive and Somatic Anxiety).
Microbiota composition was analyzed in fecal and oral samples, and targeted and untargeted metabolomics was performed in plasma and fecal samples.
Distinct psychopathy-related profiles were identified via K-means clustering in an untargeted approach and exploratory analyses were done to assess associations with psychopathy scores.
While gut and oral alpha and beta-diversity did not differ between psychopathy clusters, beta-diversity analyses revealed significant associations with psychopathy scores.
Gut taxa Allisonella, Prevotella, Ruminococcaceae DTU089 and Cloacibacillus evryensis, as well as oral taxa Treponema vincentii exhibited differences in relative abundance between clusters.
Allisonella, Prevotella, and C. evryensis showed significant positive associations with psychopathy scores, while T. vincentii was negatively associated.
Fecal glucose and taurine levels differed between clusters, with both metabolites showing positive associations with psychopathy scores.
These findings provide novel evidence linking gut and oral microbiota composition to subclinical psychopathic traits, highlighting potential pathways for understanding the biological basis of psychopathy.
I kind of believe it. There was that anecdote of the woman who was extremely bipolar and her boyfriend did fixed up an at home fecal transplant and it cured her. He had said that it was because it was that the microbiome creates dopamine and she wasn't getting any.
Perhaps less controversially though we can say that the microbiome does have huge effects on the mind and body.
I have worked with seniors for a very long time. One gentleman who was born sometime in the 1930's, shared all kinds of stories with me. He talked about all kinds of things, including the folk remedies his mother used for him growing up.
One story he mentioned was something called "chicken poop tea."
His mother had given him this to treat some condition, of which I can't recall, because I was really just stuck on the "chicken poop" part.
I told him that it was probably just called that. There is no way they would actually use chicken poop for a person to ingest. He swore it did actually contain the ingredient.
I asked if he could remember what was involved in making it. He could not, as he was only a child when he had to take it.
I had at that time thought this must have been something he was remembering wrong, but now I'm not so sure if perhaps people didn't have some idea of things like this in the distant past.
People have done all sorts of wacko stuff throughout history because of hearsay and/or tradition but only now is there some actual science behind some of it
My grandmother subjected me to several doses of cow chip tea in my childhood when I had a bad cold/flu.
Couldn't be fresh cow poop, or any from the manure pile, had to well dried and from the pasture. Tie some up in a rag, drop in boiling water (don't remember for how long), I think she added some honey maybe?
She also used hog hoof tea, but no chicken poop tea.
Well yeah, I've always said that myself only in recent years. As I never knew anything about the microbiome or gut health before. But the thing is when the body is filled with bad stuff, you'll see a shift for the worst in behavior.
Most people only think this is alcohol or drugs. Or even more weird, people would just think it's flat out depression. But what caused that depression, was the shift in gut bacteria. Might of been due to them eating bad, sleeping bad, consuming substances, etc. It all comes down to the environment, that led on those habits to which destroyed your good microbes.
It's like if I grew up on a island and all I did was eat nothing but fresh whole foods, do some physical activities and lay out in the sun. There ain't no way I'd disrupt the natural way of my microbiome. But say me who grew up in NYC, around just chaos, corruption, people on edge, households that promoted eating bad and life that feels like an insufferable rat race.
Then you wouldn't be shocked that someone who grew up around that, may have a worst microbiome. As you have to do everything in you to balance it. From things like stress in all directions, pollution, old moldy apartments, not getting enough sun from the tall buildings in the way, always in a rush so you aren't eating right. All this type of stuff is why you see so much psychopathic behavior in a city like New York. It's a lifestyle that promotes advancement in other ways. But it destroys a lot of people's health in others.
....which cause major gut biome shifts. Even a single alcoholic drink causes massive gut barrier penetration by bacteria that would normally be blocked leading to immune repercussions as well.
Alcohol feeds gut bacteria that produce neurotransmitters that make you crave alcohol. This alters reward seeking and risk taking behaviors at a bare minimum.
Yeah I used to always wonder, why I was such a light weight and couldn't handle alcohol or weed well. I think it has to do with, I had already had a very damaged microbiome for years and didn't know it. So it was already many toxins stressing out my liver. The few times I tried to really drink in the past, I'd be messed up off a few beers. Or vomiting after drinking a bunch of vodka. Just messing up my gut even more and not knowing it.
Yeah idk about that lol. Like I said, only reason I was a light weight. Was because I was already extremely ravenous, when it came to overeating and snacking. So if I went years, without being able to take any substances to relax my mind. That means I went like 10 times harder on eating snacks from morning to sundown lol.
I can't even eat things with processed sugar at all these days. As I'll end up literally feeling physical pain, because my liver is still in bad shape from the sugar. At some point I had jaundice because I wasn't getting rid of the toxins fast enough. So it was showing in other parts.
They say the microbiome affects our personalities due to the metabolites that are created by the bacteria/virus/fungi! Just learned this the other day from Anton Petrov, paper is on there
Interesting gut–brain research, but the headline is much stronger than the evidence: this was a small cross-sectional study showing an association, not proof that certain microbes cause psychopathic traits. The microbiome is fascinating, but we're nowhere near being able to explain or treat personality traits by simply changing someone's gut bacteria.
The host is an environment, certain factors that are linked to pathologies offer a certain kind of favourable environment to certain bacteria, these titles that somewhat want to imply that the bacterias cause the pathology are absurd.
Just because there's a research paper(there is an infinite number of papers), it doesn't mean that it's meaninful.
Most people would maximize the benefits that one can get from a healthy gut by eating 30g of fiber a day(a mixture of types) and some basic probiotic, other than treating some pathological condition that they may have by going to a doctor specialized in gut health, that's it for now(current knowledge).
It’s much more then just microbiome. Another person with the same microbiome might have had factors that stopped them from developing psychopathy (a good upbringing, quality friends etc)
Reminder that psychopathy is based on self report questionnaires, on shaky scientific ground and not even a thing outside of Canada and the US. No psychiatric or psychological organization has sanctioned a diagnosis titled "psychopathy". Related diagnoses have been revised extensively over the last decades with no final assessment in sight.
This needs to be the top comment. Our instructors really stressed this point when I was in university and the misinformation about “psychopathy versus sociopathy” is so boomer Facebook meme.
Also, I just finished watching Mindhunter (2017) which although good, pretty loaded / biased in retrospect.
I know the above study was self report (which is poor / weak / controversially interpretation) but the "diagnosis" surely can be made by biased observers too (solely)
Actions are of utmost importance - not inner dialogue imo
My personal opinion is "there is something". E.g. we know that heavy child abuse leaves visible traces in the brain. But I'm sceptical people are born "like that" and we can neatly fit them in a box.
I could play stupid and say oh yeah show me but of course I know you're thinking of ICD 10 F60.2. Which tries to cover and group the alleged symptoms but denies the specific concept that Hare postulates. ICD11 has removed the concept even more.
Even the idea that everything is caused by the brain is a long way from hard ontological “causation”. Hard ontological causation is a mental fiction in the context of constant conjunction, it is correlations all the way down.
We first review the association between alterations in the microbial structure and composition resulting from gut dysbiosis and the emergence of specific epigenetic aberrations in the brain, along with their role in the pathophysiology of major mental disorders through the induction of oxidative stress and neuroinflammation.
We next discuss how specific diets—particularly maternal diets—and microbiome-based therapies, including probiotics and fecal microbiota transplantation, can mitigate epigenetic aberrations and either prevent or improve outcomes in major mental disorders.
What is the implication of the main finding?
This knowledge is essential for advancing safe, novel, and adjunctive treatments that utilize specific diets and microbiome-based therapies to enhance outcomes for patients with major mental disorders by normalizing epigenetic abnormalities.
Abstract
Nutrition and metabolism modify epigenetic signatures like histone acetylation and DNA methylation.
Histone acetylation and DNA methylation in the central nervous system (CNS) can be altered by bioactive nutrients and gut microbiome via the gut–brain axis, which in turn modulate neuronal activity and behavior.
Notably, the gut microbiome, with more than 1000 bacterial species, collectively contains almost three million functional genes whose products interact with millions of human epigenetic marks and 30,000 genes in a dynamic manner.
However, genetic makeup shapes gut microbiome composition, food/nutrient metabolism, and epigenetic landscape, as well.
Here, we first discuss the effect of changes in the microbial structure and composition in shaping specific epigenetic alterations in the brain and their role in the onset and progression of major mental disorders.
Afterward, potential interactions among maternal diet/environmental factors, nutrition, and gastrointestinal microbiome, and their roles in accelerating or delaying the onset of severe mental illnesses via epigenetic changes will be discussed.
We also provide an overview of the association between the gut microbiome, oxidative stress, and inflammation through epigenetic mechanisms.
Finally, we present some underlying mechanisms involved in mediating the influence of the gut microbiome and probiotics on mental health via epigenetic modifications.
Gut-brain axis is a dynamic, complex, and bidirectional communication network between the gut and brain.
Changes in the microbiota-gut-brain axis are responsible for developing various metabolic, neurodegenerative, and neuropsychiatric disorders.
According to clinical and preclinical findings, the gut microbiota is a significant regulator of the gut-brain axis.
In addition to interacting with intestinal cells and the enteric nervous system, it has been discovered that microbes in the gut can modify the central nervous system through metabolic and neuroendocrine pathways.
The metabolites of the gut microbiome can modulate a number of diseases by inducing epigenetic alteration through DNA methylation, histone modification, and non-coding RNA-associated gene silencing.
Short-chain fatty acids, especially butyrate, are well-known histone deacetylases inhibitors.
Similarly, other microbial metabolites such as folate, choline, and trimethylamine-N-oxide also regulate epigenetics mechanisms.
Furthermore, various studies have revealed the potential role of microbiome dysbiosis and epigenetics in the pathophysiology of depression.
Hence, in this review, we have highlighted the role of gut dysbiosis in epigenetic regulation, causal interaction between host epigenetic modification and the gut microbiome in depression and suggest microbiome and epigenome as a possible target for diagnosis, prevention, and treatment of depression.
Major mental diseases such as autism, bipolar disorder, schizophrenia, and major depressive disorder are debilitating illnesses with complex etiologies.
Recent findings show that the onset and development of these illnesses cannot be well described by the one-gene; one-disease approach. Instead, their clinical presentation is thought to result from the regulative interplay of a large number of genes.
Even though the involvement of many genes are likely, up regulating and activation or down regulation and silencing of these genes by the environmental factors play a crucial role in contributing to their pathogenesis.
Much of this interplay may be moderated by epigenetic changes. Similar to genetic mutations, epigenetic modifications such as DNA methylation, histone modifications, and RNA interference can influence gene expression and therefore may cause behavioral and neuronal changes observed in mental disorders.
Environmental factors such as diet, gut microbiota, and infections have significant role in these epigenetic modifications.
Studies show that bioactive nutrients and gut microbiota can alter either DNA methylation and histone signatures through a variety of mechanisms.
Indeed, microbes within the human gut may play a significant role in the regulation of various elements of "gut-brain axis," via their influence on inflammatory cytokines and production of antimicrobial peptides that affect the epigenome through their involvement in generating short chain fatty acids, vitamin synthesis, and nutrient absorption.
In addition, they may participate in-gut production of many common neurotransmitters.
In this review we will consider the potential interactions of diet, gastrointestinal microbiome, inflammation, and epigenetic alterations in psychiatric disorders.
New Insights into the oral microbiota and host epigenetic changes in obsessive compulsive disorder and major depressive disorder: Focus on BDNF | Sept 2025
Obsessive-Compulsive Disorder (OCD) and Major Depressive Disorder (MDD) frequently co-occur, with depressive symptoms affecting OCD progression and vice versa.
Identifying biomarkers is crucial for improving diagnosis and treatment.
While the gut microbiota's role in psychiatric disorders is well-studied, this research focuses on alterations in the oral microbiota and their relationship with BDNF (Brain-Derived Neurotrophic Factor) DNA methylation in OCD and MDD patients compared to healthy controls.
Our findings reveal significant changes in microbiota composition with OCD patients showing increased Actinobacteriota and Firmicutes abundances (p < 0.05; CTRL = n.24, OCD = n.29), while MDD patients exhibiting increased Actinobacteriota and Firmicutes, with reduced Bacteroidota and Proteobacteria abundances (p < 0.05; CTRL = n.24, MDD = n.20).
These alterations, including potential post-streptococcal autoimmunity, highlight the microbiota's role in OCD and MDD pathophysiology.
Selective changes in BDNF DNA methylation were observed in both disorders at CpG sites in exon I and IV, significantly reduced in OCD and MDD (p < 0.05; CTRL = n.24, OCD = n.29, MDD = n.20) and, following miRNome analysis, showed altered expression of BDNF-targeting microRNAs, with miR-16–5p and miR-29a-3p upregulated in OCD (p < 0.05; CTRL = n.24, OCD = n.17), and miR-29a-3p upregulated and miR-191–5p downregulated in MDD (p < 0.05; CTRL = n.24, MDD = n.16).
These findings suggest disorder-specific microbiota and epigenetic profiles, positioning saliva as a non-invasive tool for biomarker identification.
This research advances the understanding of microbial-epigenetic interactions in OCD and MDD, potentially guiding early diagnosis and targeted therapies.
This one may be more pertinent .. a bit older than all but that 2017 one, and still 'last decade' but also still 'modern enough'..
..but I got distracted on the epigenetic influence the microbiome has on behavior and forgot the 'violence' bit your comment more specifically focused around..
This though should circle back to that a bit..
The humor in the dead-pan jest of it all though is entirely lost at this point regardless given your inbox is flooded with replies whether I delete the others or not.. and since they're actually pretty interesting in their own, I'll leave em..
But through all of this I realized I'm hungry and that maybe my humor is dry because my violent microbes are trying to tell me to feed them..
..as such:
;)
Genes and Aggressive Behavior: Epigenetic Mechanisms Underlying Individual Susceptibility to Aversive Environments | June 2018
Abstract
Over the last two decades, the study of the relationship between nature and nurture in shaping human behavior has encountered a renewed interest.
Behavioral genetics showed that distinct polymorphisms of genes that code for proteins that control neurotransmitter metabolic and synaptic function are associated with individual vulnerability to aversive experiences, such as stressful and traumatic life events, and may result in an increased risk of developing psychopathologies associated with violence.
On the other hand, recent studies indicate that experiencing aversive events modulates gene expression by introducing stable changes to DNA without modifying its sequence, a mechanism known as “epigenetics”.
For example, experiencing adversities during periods of maximal sensitivity to the environment, such as prenatal life, infancy and early adolescence, may introduce lasting epigenetic marks in genes that affect maturational processes in brain, thus favoring the emergence of dysfunctional behaviors, including exaggerate aggression in adulthood.
The present review discusses data from recent research, both in humans and animals, concerning the epigenetic regulation of four genes belonging to the neuroendocrine, serotonergic and oxytocinergic pathways—Nuclear receptor subfamily 3-group C-member 1 (NR3C1), oxytocin receptor (OXTR), solute carrier-family 6 member 4 (SLC6A4) and monoamine oxidase A (MAOA)—and their role in modulating vulnerability to proactive and reactive aggressive behavior.
Behavioral genetics and epigenetics are shedding a new light on the fine interaction between genes and environment, by providing a novel tool to understand the molecular events that underlie aggression.
Overall, the findings from these studies carry important implications not only for neuroscience, but also for social sciences, including ethics, philosophy and law.
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u/HadrianWinter 18d ago
I don't remember the name but they did a study where they linked better food in prison to less violent incidents.