Memory

Preventing human infections with dietary fibers

gettingwell4 4-5 stars Advanced knowledge, Brain development, Epigenetics, Hypothalamus, Immune system, Limbic system, Memory, Stress , , , ,

This 2020 review covered interactions of gut microbiota, intestinal mucus, and dietary fibers. I’ve outlined its headings and subheadings, and ended with its overview:

“I. Dietary fibers and human mucus-associated polysaccharides: can we make an analogy?

I.1 Brief overview of dietary fibers and mucus polysaccharides structures and properties

I.I.1 Dietary fibers

  • Dietary fiber intake and health effects

I.I.2 Intestinal mucus polysaccharides

  • Structure
  • Main functions

I.2 Similarities and differences between dietary fibers and mucus carbohydrates

  • Origin and metabolism
  • Structure

II. Interactions of dietary fibers and mucus-associated polysaccharides with human gut microbiota

II-1 Substrate accessibility and microbial niches

  • Dietary fibers
  • Mucus polysaccharides

II-2 Recognition and binding strategies

  • Dietary fibers
  • Mucus polysaccharides

II-3 Carbohydrate metabolism by human gut microbiota

II-3.1 Specialized carbohydrate-active enzymes

II-3.2 Vertical ecological relationships in carbohydrate degradation

  • Dietary fibers
  • Mucus polysaccharides

II-3.3 Horizontal ecological relationships in carbohydrate degradation

II.4 Effect of carbohydrates on gut microbiota composition and sources of variability

II.4.1 Well-known effect of dietary fibers on the gut microbiota

II.4.2 First evidences of a link between mucus polysaccharides and gut microbiota composition

III. Gut microbiota, dietary fibers and intestinal mucus: from health to diseases?

[no III.1]

III.2 Current evidences for the relationship between dietary fibers, mucus and intestinal-inflammatory related disorder

III.2.1 Obesity and metabolic-related disorders

  • Dietary fibers
  • Mucus polysaccharides

III.2.2 Inflammatory bowel diseases

  • Dietary fibers
  • Mucus polysaccharides

III.2.3 Colorectal cancer

  • Dietary fibers
  • Mucus polysaccharides

IV. How enteric pathogens can interact with mucus and dietary fibers in a complex microbial background?

IV.1 Mucus-associated polysaccharides: from interactions with enteric pathogens to a cue for their virulence?

IV.1.1 Pathogens binding to mucus

  • Binding structures
  • Sources of variations

IV.1.2 Mucus degradation by pathogens

  • Bacterial mucinases
  • Glycosyl hydrolases

IV.1.3 Mucus-based feeding of pathogens

  • Primary degraders or cross-feeding strategies
  • Importance of microbial background

IV.1.4 Pathogens and inflammation in a mucus-altered context

IV.1.5 Modulation of virulence genes by mucus degradation products

IV.2 How can dietary fiber modulate enteric pathogen virulence?

IV.2.1 Direct antagonistic effect of dietary fibers on pathogens

  • Bacteriostatic effect
  • Inhibition of cell adhesion
  • Inhibition of toxin binding and activity

IV.2.2 Indirect effect of dietary fibers through gut microbiota modulation

  • Modulation of microbiota composition
  • Modulation of gut microbiota activity

IV.2.3 Inhibition of pathogen interactions with mucus: a new mode of dietary fibers action?

  • Binding to mucus: dietary fibers acting as a decoy
  • Inhibition of mucus degradation by dietary fibers

V. Human in vitro gut models to decipher the role of dietary fibers and mucus in enteric infections: interest and limitations?

V.1 Main scientific challenges to be addressed

V.2 In vitro human gut models as a relevant alternative to in vivo studies

V.3 In vitro gut models to decipher key roles of digestive secretions, mucus and gut microbiota

V.4 Toward an integration of host responses

V.5 From health to disease conditions

dietary fibers prevent infections

Overview of the potential role of dietary fibers in preventing enteric infections. Reliable and converging data from scientific literature are represented with numbers in circles, while data more hypothetical needing further investigations are represented with numbers in squares.

  1. Some dietary fibers exhibit direct bacteriostatic effects against pathogens.
  2. Dietary fiber degradation leads to short-chain fatty acids (SCFAs) production that can modulate pathogens’ virulence.
  3. By presenting structure similarities with receptors, some dietary fibers can prevent pathogen adhesin binding to their receptors.
  4. By the same competition mechanism, dietary fibers can also prevent toxins binding to their receptors.
  5. Dietary fibers are able to promote gut microbiota diversity.
  6. Dietary fibers may promote growth of specific strains with probiotic properties and therefore exhibit anti-infectious properties.
  7. Suitable dietary fiber intake prevents microbiota’s switch to mucus consumption, limiting subsequent commensal microbiota encroachment and associated intestinal inflammation.
  8. Dietary fibers may prevent pathogen cross-feeding on mucus by limiting mucus degradation and/or by preserving diversity of competing bacterial species.
  9. By preventing mucus over-degradation by switcher microbes, dietary fibers can hamper pathogen progression close to the epithelial brush border, and further restrict subsequent inflammation.”

https://doi.org/10.1093/femsre/fuaa052 “Tripartite relationship between gut microbiota, intestinal mucus and dietary fibers: towards preventive strategies against enteric infections” (not freely available)

There were many links among gut microbiota studies previously curated. For example, Go with the Alzheimer’s Disease evidence found:

“Akkermansia cannot always be considered a potentially beneficial bacterium. It might be harmful for the gut–brain axis in the context of AD development in the elderly.”

The current review provided possible explanations:

“Akkermansia muciniphila could be considered as a species that fulfills a keystone function in mucin degradation. It is a good example of a mucus specialist.”

Points #7-9 of the above overview inferred that insufficient dietary fiber may disproportionately increase abundance of this species. But Gut microbiota strains also found that effects may be found only below species at species’ strain levels.

These reviewers provided copies in places other than what’s linked above. Feel free to contact them for a copy.

Moon bandit

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No magic bullet, only magical thinking

gettingwell4 4-5 stars Advanced knowledge, Cerebrum, Dopamine, Epigenetics, Hypothalamus, Immune system, Limbic system, Memory, Neurochemicals, Stress , ,

Consider this a repost of Dr. Paul Clayton’s blog post The Drugs Don’t Work:

“The drug industry has enough funds to:

  • Rent politicians;
  • Subvert regulatory agencies;
  • Publish fake data in the most august peer-reviewed literature; and
  • Warp the output of medical schools everywhere.

Their products are a common cause of death. Every year, America’s aggressively modern approach to disease kills over 100,000 in-hospital patients, and twice that number of out-patients.

In 1900, a third of all deaths occurred in children under the age of 5. By 2000 this had fallen to 1.4%. The resulting 30-year increase in average life expectancy fed into the seductive and prevailing myth that we are all living longer; which is manifestly untrue. Improvements in sanitation were far more significant in pushing infections back than any medical developments.

There is currently no pharmaceutical cure for Alzheimer’s or Parkinsonism, nor can there be when these syndromes are in most cases driven by multiple metabolic distortions caused by today’s diet. The brain is so very complex, and it can go wrong in so many ways. The idea that we can find a magic bullet for either of these syndromes is ill-informed and philosophically mired in the past.

It is also dangerous. There is a significant sub-group of dementia sufferers whose conditions are driven and exacerbated by pharmaceuticals. Chronic use of a number of commonly prescribed drugs – and ironically, anti-Parkinson drugs – increases the risk of dementia by roughly 50%.

Big Pharma’s ability to subvert regulatory authorities is even more dangerous. The recent FDA approval of Biogen’s drug aducanumab is a scandal; not one member of the FDA Advisory Committee voted to approve this ineffective product, and three of them resigned in the aftermath of the FDA’s edict. This ‘anti-Alzheimer’s’ drug, which will earn Biogen $56,000 / patient / year, was licensed for financial reasons; it reduced amyloid plaque but was clinically ineffective.

So did the eagerly awaited gantenerumab and solanezumab. But they, too, failed to produce any significant clinical benefit.”

A knee-replacement patient enduring her daily workout

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Eating sprouts prevents AGEs

gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Immune system, Memory, Stress ,

This 2021 in vitro study found:

“Prolonged and chronic hyperglycemia is a leading factor in inducing formation of advanced glycation end-products (AGEs) generated by reaction of free amino groups of proteins and carbonyl groups in reducing sugars, especially glucose and fructose. Metabolism of glucose via the glycolysis pathway also produces the most reactive compounds such as methylglyoxal (MG), a potent precursor of AGEs.

Previous studies reported that red cabbage extract could decrease glycated hemoglobin concentration in streptozotocin-induced diabetic rats and oxidative stress makers including protein carbonyl content and malondialdehyde in red blood cells. Emerging evidence supports that inhibition of protein glycation and oxidative damage may be attributed to free radical scavenging activity of plant extracts.

three brassicae

Extracts of Brassica vegetables cauliflower, cabbage and Chinese cabbage:

  • Inhibited formation of AGEs;
  • Prevented loss of protein thiol group; and
  • May act as a MG-trapping and antioxidant agent.

Phenolic acids, particularly sinapic acid and p-hydroxybenzoic acid, were commonly found in Brassica vegetables. These findings suggest that Brassica vegetables may be promising antiglycation and antioxidant agents for preventing formation of AGEs.”

https://link.springer.com/article/10.1007/s11130-021-00903-w “Phytochemical Composition, Antiglycation, Antioxidant Activity and Methylglyoxal‑Trapping Action of Brassica Vegetables” (not freely available)

Regarding this study’s sinapic acid findings, Broccoli sprout compounds include sinapic acid derivatives found with 6-day-old broccoli sprouts:

“Sprouting in darkness results in overall decrease in total content of sinapic acid derivatives with growth time, but promotes replacement of relatively low active constituents, such as sinapine, by stronger antioxidants. These structural changes are beneficial for total antioxidant capacity of broccoli sprouts, and are correlated with their increasing ability to scavenge free radicals, reduce transition metal ions, and inhibit lipid peroxidation.”

Regarding this study’s p-hydroxybenzoic acid findings, Advantages of 3-day-old oat sprouts over oat grains found with 3-day-old oat sprouts:

“Six hydroxybenzoic acids were found in greater amounts in sprouts, whereas two were reduced or lost.”

Getting onboard before sunrise

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Gut microbiota functional relationships

gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Immune system, Memory, Stress , ,

This 2021 study investigated environmentally-organized gut microbiome functional relationships:

“There has been a substantial gap between understanding microbiome assemblage and how its functionality is organized. In this study, we demonstrated the usefulness of metaproteomics in gaining a system-level understanding of microbiome functionality.

Our current finding highlights the value of further investigation into functional hubs and hub functions in microbiome proteomic content networks. This will provide a unique and systematic insight for prediction of community functional responses, or manipulation of microbiome functioning.

Across all metaproteomics datasets, Eubacterium, Faecalibacterium, Ruminococcus, Bacteroides, Clostridium and Coprococcus were found to be the most frequent functional hubs.

functionally related genera

Taxon-function bipartite network based on functional distances between microbial genera. Size of a node corresponds to its degree.

Highly connected functions were enriched in metabolism of carbohydrates and amino acids, suggesting that microbial acquisition of nutrients from the environment and trophic interactions between microbes could be major factors that shape their active functional organization. Our result showing robustness of between-taxa functional distances across individual microbiomes implied a more fundamental mechanism that underlies selective organization of microbiome functionalities by environment.

We observed a universal pattern of between-taxa functional distances (dij) across all analyzed datasets. Notably, this pattern was fully shifted by a global increase in dij values, and subsequently a significant decrease of normalized taxonomic diversity in a subset of inflammatory bowel disease samples mostly obtained from inflamed areas.

This finding may support, from a functional angle, the hypothesis that there are alternative stable states (bi-stability or multi-stability) in the gut ecosystem. One frequently discussed mechanism behind these alternative states has been continuous exposure of the microbiome to a altered environmental parameter:

  • An inflamed area in the gut will have a reduced mucus layer and elevated host defense responses.
  • Host mucus layer is a nutritional source of cross-feeding in the gut microbiome.
  • Loss of this layer may firstly affect network hub functions of carbohydrate and amino acid metabolism, and subsequently affect functional interactions in the whole community.

In addition, host defense responses attenuate microbial oxidative stress responses, which have been associated to microbiome dysfunction. Decrease of within-sample functional redundancy has been associated with impaired microbiome stability and resilience.

Resilient microbiota resist external pressures and return to their original state. A non-resilient microbiome is likely to shift its composition permanently and stay at an altered new state instead of restoring to its original state of equilibrium.”

https://www.biorxiv.org/content/10.1101/2021.07.15.452564v1.full “Revealing Protein-Level Functional Redundancy in the Human Gut Microbiome using Ultra-deep Metaproteomics”

My top genus Faecalibacterium – a cross-feeding, acetate-consuming, butyrate-producing commensal – would be more than twice the size of this study’s Faecalibacterium network projection in the above graphic. In this year’s efforts to make my gut microbiota happy, I’ve apparently done much to express its relevant gene network.

my genera

I came across this study by it citing Gut microbiota guilds.

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Microwave your Brassica vegetables

gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Immune system, Memory, Stress

This 2021 review evaluated effects on glucoraphanin and sulforaphane content of cooking broccoli and other Brassica vegetables:

“The amount of glucosinolates (GLS) in brassica vegetables can be affected significantly during processing and cooking, depending on their specific conditions and types:

  • Microwaving can retain or even increase content of glucoraphanin (GLR), and can increase production of sulforaphane (SLR) within a short time;
  • Fermentations generally decrease content of GLR;
  • Short-time steaming may promote formation of SLR; and
  • Short-time microwaving may promote formation of SLR from GLR better than fermentation and steaming.

Other processing and cooking effects include:

  • Packaging and freezing can reduce loss of GLR content. Freezing treatment promotes hydrolysis of GLS to form SLR, and freezing stress may lead to GLS degradation;
  • Boiling and blanching result in the largest loss of GLR from broccoli, as loss of GLR content is mainly due to its leakage into the water; and
  • Stir-frying may be a suitable and healthful cooking option to prevent loss of GLR, but contents of GLR and SLR were still influenced due to different factors.

It is better for consumers to microwave or steam brassica vegetables before consumption to obtain greater health benefits.”

https://www.sciencedirect.com/science/article/abs/pii/S030881462101013X “The effect of processing and cooking on glucoraphanin and sulforaphane in brassica vegetables” (not freely available). Thanks to Dr. Jing Sun for providing a copy.

This review found mainly negative effects of cooking Brassica vegetables with boiling, stir frying, blanching, or high pressure on glucoraphanin and sulforaphane content. Previously curated studies cited were:

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Blue heron on its way to the breakfast buffet

Prevent your brain from shrinking

gettingwell4 4-5 stars Advanced knowledge, Brainstem, Cerebellum, Cerebrum, Epigenetics, Hippocampus, Immune system, Limbic system, Lower brain, Memory, Stress , ,

My 800th curation is a 2021 human diet and lifestyle study:

“Brain atrophy is correlated with risk of cognitive impairment, functional decline, and dementia. This study (a) examines the statistical association between brain volume (BV) and age for Tsimane, and (b) compares this association to that of 3 industrialized populations in the United States and Europe.

Tsimane forager-horticulturists of Bolivia have the lowest prevalence of coronary atherosclerosis of any studied population, and present few cardiovascular disease (CVD) risk factors. They have a high burden of infections and inflammation, reflected by biomarkers of chronic immune activation, including higher leukocytes counts, faster erythrocyte sedimentation rates, and higher levels of C-reactive protein, interleukin-6, and immunoglobulin-E than in Americans of all ages.

The Tsimane have endemic polyparasitism involving helminths and frequent gastrointestinal illness. Most morbidity and mortality in this population is due to infections.

brain volume

The Tsimane exhibit smaller age-related BV declines relative to industrialized populations, suggesting that their low CVD burden outweighs their high, infection-driven inflammatory risk. If:

  1. Cross-sectional data (which we believe are population-representative of Tsimane adults aged 40 and older) represent well the average life course of individuals; and
  2. The Tsimane are representative of the baseline case prior to urbanization;

these results suggest a ~70% increase in the rates of age-dependent BV decrease accompanying industrialized lifestyles.

Despite its limitations, this study suggests:

  • Brain atrophy may be slowed substantially by lifestyles associated with very low CVD risk; and
  • There is ample scope for interventions to improve brain health, even in the presence of chronically high systemic inflammation.

Lastly, the slow rate of age-dependent BV decrease in the Tsimane raises new questions about dementia, given the role of both infections and vascular factors in dementia risk.”

https://gurven.anth.ucsb.edu/sites/default/files/sitefiles/papers/irimiaetal2021.pdf “The indigenous South American Tsimane exhibit relatively modest decrease in brain volume with age despite high systemic inflammation”

I came across this study by its citation in Dr. Paul Clayton’s 2021 blog post We’ve got to get ourselves back to the garden.

Resistant starch therapy

gettingwell4 5+ stars Premium, Epigenetics, Immune system, Memory, Stress ,

This 2021 review subject was interactions among resistant starches and gut microbiota:

“Starch that reaches the large intestine without being fully digested is termed resistant starch (RS). Starch digestibility should be considered as a kinetic property (slower to faster) affected by host-specific factors, rather than as a binary trait (resistant or nonresistant).

RS is degraded by the colon’s complex ecosystem of microbes, triggering a cascading web of metabolic interactions. RS acts as a resource that is degraded and fermented by a hierarchy of specialized gut microbes:

  1. Primary degraders grow on RS in monoculture. They penetrate outer surfaces of intact RS granules, exposing pores and deeper concentric matrices while liberating oligosaccharides and generating metabolites like lactate and acetate.
  2. Secondary degraders grow on starch in monoculture, but degrade intact RS poorly or not at all. Instead, they may adhere to abrasions and pores on RS before participating in its degradation, and opportunistically utilize solubilized oligosaccharides produced by other RS degraders.
  3. Cross-feeders do not grow on starch in monoculture. They utilize by-products generated by upstream degraders, helping to maintain stoichiometric equilibrium and thermodynamically favorable (i.e. unconstrained) fermentation.

Together, the subsystem of microbes involved in RS degradation and fermentation participates in a complex network of cross-feeding interactions. In maintaining microbiome homeostasis, the RS nutrient web expands the scope of what could be considered a ‘beneficial’ gut microbe to a cluster of metabolically interconnected microbes.

1. Primary degraders such as acetate-producing Ruminococcus bromii are thought to be necessary for RS degradation in the human gut, where they unlock RS for other community members to degrade and ferment.

Ruminococcus genus

2. Secondary degraders possess extracellular amylases to degrade regular starch, but their contribution to initiating RS degradation is negligible compared to that of primary degraders. Instead, they may require primary degraders to erode smooth RS granule surfaces before adhering to RS and/or scavenging for ‘substrate spillover’ (i.e. excess oligosaccharides generated by primary degraders).

Eubacterium genus

Roseburia genus

3. Cross-feeders utilize starch by-products or metabolites generated by upstream RS degraders, such as acetate, lactate, formate, and succinate. Describing all known gut bacteria capable of utilizing these substrates exceeds the scope of this review, but one other example is noteworthy.

Faecalibacterium prausnitzii is a prominent butyrate-producing commensal, comprising 1.5% to 9.5% of fecal bacteria in European individuals. F. prausnitzii utilizes maltose and acetate to generate butyrate.

top 1-10 species

Microbiome sequencing data are compositional, meaning that gene amplicon read counts do not necessarily reflect bacterial absolute abundances. Instead, read counts are typically normalized to sum to 100%.

For this reason, relative abundances of smaller keystone communities (e.g. primary degraders) may increase, but appear to decrease simply because cross-feeders increase in relative abundance to a greater extent. These limitations illustrate the necessity of sufficiently powering RS interventions where microbiome composition is the primary endpoint, collecting critical baseline data and employing appropriate statistical techniques.”

https://www.tandfonline.com/doi/full/10.1080/19490976.2021.1926842 “Resistant starch, microbiome, and precision modulation”

Part 3 of Make your gut microbiota happy

gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Immune system, Memory, Stress ,

Continuing from Part 2, my 7/15/2021 sample found that no bad bacteria needed work. Top three reasons why this may be are:

1. I’ve eaten microwaved broccoli sprouts every day for 68 weeks now. Relevant research:

helicobacter 0

2. This is the 17th year of training my immune system every day with yeast cell wall β-glucan.

acinetobacter

3. Basic hygiene practices such as brushing my teeth twice a day.

aggregatibacter 0

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A time to speak

gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Glutamate, Immune system, Memory, Neurochemicals

“To every thing there is a season, and a time to every purpose under heaven:
A time to break down, and a time to build up;
A time to dance, and a time to mourn;
A time you may embrace, and a time to refrain from embracing;
A time to keep silent, and a time to speak.”

A review from 2017:

“Few, if any, other drugs can rival ivermectin for its beneficial impact on human health and welfare. Perhaps more than any other drug, ivermectin is a drug for the world’s poor. For most of this century, some 250 million people have been taking it.

The following are an indication of disease-fighting potential that has been identified for ivermectin thus far:

  • Antiviral – Ivermectin has been found to potently inhibit replication of yellow fever virus, with EC50 values in the sub-nanomolar range. It inhibits replication in several other flaviviruses, including dengue, Japanese encephalitis, and tick-borne encephalitis. Ivermectin interrupts virus replication. It demonstrates antiviral activity against several RNA viruses by blocking nuclear trafficking of viral proteins. It has been shown to have potent antiviral action against HIV-1.
  • Asthma – Ivermectin suppressed mucus hypersecretion by goblet cells, establishing that ivermectin can effectively curb inflammation, such that it may be useful in treating allergic asthma and other inflammatory airway diseases.
  • Bedbugs – Ivermectin is highly effective against bedbugs, capable of eradicating or preventing bedbug infestations.
  • Disease vector control – Ivermectin is highly effective in killing a broad range of insects. Comprehensive testing against 84 species of insects showed that avermectins were toxic to almost all insects tested. At sub-lethal doses, ivermectin inhibits feeding and disrupts mating behavior, oviposition, egg hatching, and development.
  • Malaria – Mosquitoes that transmit Plasmodium falciparum, the most dangerous malaria-causing parasite, can be killed by ivermectin present in the human bloodstream after a standard oral dose.
  • Myiasis – Myiasis is an infestation of fly larvae that grow inside the host. Oral myiasis has been successfully treated with ivermectin, which has also been effective as a non-invasive treatment for orbital myiasis, a rare and preventable ocular morbidity.
  • Schistosomiasis – Schistosoma species are the causative agent of schistosomiasis, a disease afflicting more than 200 million people worldwide. Ivermectin helps control one of the world’s major neglected tropical diseases.
  • Trichinosis – Globally, approximately 11 million individuals are infected with Trichinella roundworms. Ivermectin kills Trichinella spiralis, the species responsible for most of these infections.”

https://www.nature.com/articles/ja201711 “Ivermectin: enigmatic multifaceted ‘wonder’ drug continues to surprise and exceed expectations”

72 citations in CrossRef. Didn’t see citing 2020-2021 papers that noted any safety concerns when administered at proper doses.

Train your immune system every day, because:

“Rapid clearance following ivermectin dosing, results not from direct impact of the drug, but via suppression of a parasite’s ability to evade the host’s natural immune defense mechanisms.”

It’s safe, and it’s effective. Ivermectin’s main difficulty is that its patent expired in 1997.

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PTSD susceptibility?

gettingwell4 2-3 stars Required further work, Amygdala, Epigenetics, Hippocampus, Limbic system, Memory, Primal Therapy, Stress , , , , , , ,

This 2021 rodent study investigated post-traumatic stress disorder (PTSD) susceptibility:

“PTSD is an incapacitating trauma-related disorder, with no reliable therapy. We show distinct DNA methylation profiles of PTSD susceptibility in the nucleus accumbens (NAc). Data analysis revealed overall hypomethylation of different genomic CpG sites in susceptible animals.

Is it possible to treat PTSD by targeting epigenetic processes? Such an approach might reverse genomic underpinning of PTSD and serve as a cure.

To test plausibility of such an approach, a reliable animal (rat) model with high construct validity is needed. Previously, we reported one such model, which uses predator-associated trauma, and cue reminders to evoke recurring trauma. This simulates clinical PTSD symptoms including re-experiencing, avoidance, and hyperarousal.

Individual PTSD-like (susceptible) behavior is analyzed, enabling identification of susceptible animals separately from those that are non-PTSD-like (resilient). This model captures salient features of this disorder in humans, in which only a fraction of trauma victims develop PTSD, while others are resilient.

experimental model

Sprague–Dawley rats were exposed to trauma and to three subsequent trauma-associated reminders. Freezing behavior was measured under conditions of:

  • Exploration;
  • Social interaction (with a companion); and
  • Hyperarousal.

Controls were exposed to identical conditions except for the traumatic event.

PTSD-like behavior of each animal was compared with baseline and with the population. Two unambiguous sub-populations were identified, resilient and susceptible.

After exposure to trauma and its reminders, susceptible animals showed an increase from baseline in freezing behavior, and over time in all three behavioral tests, as opposed to resilient and control groups.

DMRs

Differentially methylated sites in susceptible and resilient animals compared to control group.

Although we focused in this study on DNA methylation changes that associate with susceptibility, we also report unique changes in DNA methylation that occur in resilient animals. Inhibition of critical genes that are downregulated in susceptible animals convert resilient animals to become susceptible.”

https://www.researchgate.net/publication/353192082_Reduction_of_DNMT3a_and_RORA_in_the_nucleus_accumbens_plays_a_causal_role_in_post-traumatic_stress_disorder-like_behavior_reversal_by_combinatorial_epigenetic_therapy “Reduction of DNMT3a and RORA in the nucleus accumbens plays a causal role in post-traumatic stress disorder-like behavior: reversal by combinatorial epigenetic therapy” (registration required)

Rodents with the same genetics and environment displayed individual differences in their responses to traumatic events. Researchers, provide evidence for that before venturing elsewhere.

Not sure why it took 3+ years for this study received in November 2017 to finally be published in July 2021. Sites other than https://doi.org/10.1038/s41380-021-01178-y are more transparent about their peer review and publication processes.

No causes for PTSD susceptibility were investigated. PTSD effects and symptoms aren’t causes, notwithstanding this study’s finding that:

“Our results support a causal role for the NAc as a critical brain region for expression of PTSD-like behaviors, and a role for programming genes by DNA methylation in the NAc in development of PTSD-like behaviors.”

Can’t say that I understand more about causes for PTSD susceptibility now than before I read this study. Researchers attaching significance to gene functional groups seemed like hypothesis-seeking efforts to overcome limited findings.

Will this study’s combination of a methyl donor with a Vitamin A metabolite address PTSD causes in humans? If it only temporarily alleviates symptoms, what lasting value will it have?

Several brain and body areas that store traumatic memories other than the nucleus accumbens were mentioned in The role of recall neurons in traumatic memories. A wide range of epigenetic memory storage vehicles is one reason why effective human therapies need to address each individual, their whole body, and their entire history.

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Osprey breakfast

Gut and brain health

gettingwell4 2-3 stars Required further work, Amygdala, Brain development, Brain hemispheres, Brainstem, Cerebrum, Cortisol, Dopamine, Epigenetics, Glutamate, Hippocampus, Hypothalamus, Immune system, Limbic system, Lower brain, Memory, Neurochemicals, Oxytocin, Serotonin, Stress, Testosterone , , , ,

This 2021 human review subject was interactions of gut health and disease with brain health and disease:

“Actions of microbial metabolites are key for appropriate gut-brain communication in humans. Among these metabolites, short-chain fatty acids (SCFAs), tryptophan, and bile acid metabolites / pathways show strong preclinical evidence for involvement in various aspects of brain function and behaviour.

Dietary fibres, proteins, and fats ingested by the host contain components which are metabolized by microbiota. SCFAs are produced from fermentation of fibres, and tryptophan-kynurenine (TRP-KYN) metabolites from dietary proteins. Primary bile acids derived from liver metabolism aid in lipid digestion, but can be deconjugated and bio-transformed into secondary bile acids.

1-s2.0-S0149763421001032-gr1

One of the greatest challenges with human microbiota studies is making inferences about composition of colonic microbiota from faeces. There are known differences between faecal and caecal microbiota composition in humans along with spatial variation across the gastrointestinal tract.

It is difficult to interpret microbiome-host associations without identifying the driving influence in such an interaction. Large cohort studies may require thousands of participants on order to reach 20 % explanatory power for a certain host-trait with specific microbiota-associated metrics (Shannon diversity, relative microbial abundance). Collection of metadata is important to allow for a better comparison between studies, and to identify differentially abundant microbes arising from confounding variables.”

https://www.sciencedirect.com/science/article/pii/S0149763421001032 “Mining Microbes for Mental Health: Determining the Role of Microbial Metabolic Pathways in Human Brain Health and Disease”

Don’t understand why these researchers handcuffed themselves by only using PubMed searches. For example, two papers were cited for:

“Conjugated and unconjugated bile acids, as well as taurine or glycine alone, are potential neuroactive ligands in humans.”

Compare scientific coverage of PubMed with Scopus:

  • 2017 paper: PubMed citations 39; Scopus citations 69.
  • 2019 paper: PubMed citations 69; Scopus citations 102.

Large numbers of papers intentionally missing from PubMed probably influenced this review’s findings, such as:

  1. “There are too few fibromyalgia and migraine microbiome-related studies to make definitive conclusions. However, one fibromyalgia study found altered microbial species associated with SCFA and tryptophan metabolism, as well as changes in serum levels of SCFAs. Similarly, the sole migraine-microbiota study reported an increased abundance of the kynurenine synthesis GBM (gut-brain module).
  2. Due to heterogeneity of stroke and vascular disease conditions, it is difficult to make substantial comparisons between studies. There is convincing evidence for involvement of specific microbial genera / species and a neurovascular condition in humans. However, taxa were linked to LPS biosynthesis rather than SCFA production.
  3. Several studies suggest lasting microbial changes in response to prenatal or postnatal stress, though these do not provide evidence for involvement of SCFA, tryptophan, or bile-acid modifying bacteria. Similar to stress, there are very few studies assessing impact of post-traumatic stress disorder on microbiota.”

These researchers took on a difficult task. Their study design could have been better.

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Wildlife

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Take acetyl-L-carnitine for early-life trauma

gettingwell4 2-3 stars Required further work, Amygdala, Brain development, Brain hemispheres, Cerebrum, Dopamine, Epigenetics, Glutamate, Hippocampus, Hypothalamus, Limbic system, Memory, Neurochemicals, Oxytocin, Primal Therapy, Serotonin, Stress , , , , , , , ,

This 2021 rodent study traumatized female mice during their last 20% of pregnancy, with effects that included:

  • Prenatally stressed pups raised by stressed mothers had normal cognitive function, but depressive-like behavior and social impairment;
  • Prenatally stressed pups raised by control mothers did not reverse behavioral deficits; and
  • Control pups raised by stressed mothers displayed prenatally stressed pups’ behavioral phenotypes.

“Acetyl-L-carnitine (ALCAR) protected against and reversed depressive-like behavior induced by prenatal trauma:

alcar regime

ALCAR was supplemented in drinking water of s → S mice either from weaning to adulthood (3–8 weeks), or for one week in adulthood (7–8 weeks). ALCAR supplementation from weaning rendered s → S mice resistant to developing depressive-like behavior.

ALCAR supplementation for 1 week during adulthood rescued depressive-like behavior. One week after ALCAR cessation, however, the anti-depressant effect of ALCAR was diminished.

Intergenerational trauma induces social deficits and depressive-like behavior through divergent and convergent mechanisms of both in utero and early-life parenting environments:

  • We establish 2-HG [2-hydroxyglutaric acid, a hypoxia and mitochondrial dysfunction marker, and an epigenetic modifier] as an early predictive biomarker for trauma-induced behavioral deficits; and
  • Demonstrate that early pharmacological correction of mitochondria metabolism dysfunction by ALCAR can permanently reverse behavioral deficits.”

https://www.nature.com/articles/s42003-021-02255-2 “Intergenerational trauma transmission is associated with brain metabotranscriptome remodeling and mitochondrial dysfunction”

This study had an effusive endorsement of acetyl-L-carnitine in its Discussion section, ending with:

“This has the potential to change lives of millions of people who suffer from major depression or have risk of developing this disabling disorder, particularly those in which depression arose from prenatal traumatic stress.”

I take a gram daily. Don’t know about prenatal trauma, but I’m certain what happened during my early childhood.

I asked both these researchers and those of Reference 70 for their estimates of a human equivalent to “0.3% ALCAR in drinking water.” Will update with their replies.

No word from those researchers, so here’s what I calculate:

  • (.003 x .081) x 70 kg = 1.7% human equivalent dose.
  • 1 liter water = 1 kg, so .017 x 1000 g = 17 g per liter of water.

We all drink at least a liter of water every day. A 17 gram/liter dose is way too high for humans, considering:

I downgraded this study to Required further work. It’s likely these researchers overdosed mice to ensure their treatment produced an effect. That’s counterproductive to the purpose of animal studies: to help humans.

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Week 63 of Changing to a youthful phenotype with sprouts

gettingwell4 4-5 stars Advanced knowledge, Epigenetics, Memory, Stress

Finally got around to getting an annual physical this morning. Two indicators so far, with more expected in five days. They came in early, so here’s Part 2.

1. HbA1C – glycated hemoglobin – was 4.8 on a scale of 4.8 to 5.6%. That’s down from 5.1 in June 2020. HbA1C shows a two-month average blood glucose level.

I’ve eaten advanced glycation end product (AGE)-less chicken vegetable soup almost every day since July 2019. Upcoming instantaneous blood glucose measurements may be informative, but it seems that with what I’m doing, there’s little impetus to glycate that glucose. Which satisfies my intention to avoid glycative stress.

2. BMI for a normal weight is 18.5-24.9 kg/m2. Measurements over the past two years:

  • June 2019 24.8, 0.1 below range high;
  • June 2020 22.4, 2.5 below range high and 3.9 above low; and
  • June 2021 21.0, 3.9 below range high and 2.5 above low.

Annual BMI trend is going in the right direction, but it’s too squishy to be a biomarker. I usually don’t curate studies that rely on BMI.

I eat a lot of food every day! Not going to turn my kitchen into a laboratory to quantify, though. See Switch on your Nrf2 signaling pathway for what intake was on 1/1/2021.

Once or twice a week lately I’ve backed off and skipped one of a daily two (fresh and leftovers) AGE-less chicken vegetable meals when it’s been too much food. Haven’t skipped:

  • Twice-daily combined broccoli-red cabbage-mustard sprouts; or
  • Twice-daily Avena sativa oat sprouts; or
  • My Avena nuda whole oats breakfast.

Lost 11 lbs. over 12 months without trying to lose weight. Maximal food intake didn’t result in weight gain when much of its purpose was to:

  • Reduce inflammation; and
  • Make my gut microbiota happy.

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