Taurine week #7: Brain

Finishing a week’s worth of 2022 taurine research with two reviews of taurine’s brain effects:

“We provide a overview of brain taurine homeostasis, and review mechanisms by which taurine can afford neuroprotection in individuals with obesity and diabetes. Alterations to taurine homeostasis can impact a number of biological processes such as osmolarity control, calcium homeostasis, and inhibitory neurotransmission, and have been reported in both metabolic and neurodegenerative disorders.

Models of neurodegenerative disorders show reduced brain taurine concentrations. On the other hand, models of insulin-dependent diabetes, insulin resistance, and diet-induced obesity display taurine accumulation in the hippocampus. Given cytoprotective actions of taurine, such accumulation of taurine might constitute a compensatory mechanism that attempts to prevent neurodegeneration.


Taurine release is mainly mediated by volume-regulated anion channels (VRAC) that are activated by hypo-osmotic conditions and electrical activity. They can be stimulated via glutamate metabotropic (mGluR) and ionotropic receptors (mainly NMDA and AMPA), adenosine A1 receptors (A1R), and metabotropic ATP receptors (P2Y).

Taurine mediates its neuromodulatory effects by binding to GABAA, GABAB, and glycine receptors. While taurine binding to GABAA and GABAB is weaker than to GABA, taurine is a rather potent ligand of the glycine receptor. Reuptake of taurine occurs via taurine transporter TauT.

Cytoprotective actions of taurine contribute to brain health improvements in subjects with obesity and diabetes through various mechanisms that improve neuronal function, such as:

  • Modulating inhibitory neurotransmission, which promotes an excitatory–inhibitory balance;
  • Stimulating antioxidant systems; and
  • Stabilizing mitochondria energy production and Ca2+ homeostasis.”

https://www.mdpi.com/2072-6643/14/6/1292/htm “Taurine Supplementation as a Neuroprotective Strategy upon Brain Dysfunction in Metabolic Syndrome and Diabetes”

A second review focused on taurine’s secondary bile acids produced by gut microbiota:

“Most neurodegenerative disorders are diseases of protein homeostasis, with misfolded aggregates accumulating. The neurodegenerative process is mediated by numerous metabolic pathways, most of which lead to apoptosis. Hydrophilic bile acids, particularly tauroursodeoxycholic acid (TUDCA), have shown important anti-apoptotic and neuroprotective activities, with numerous experimental and clinical evidence suggesting their possible therapeutic use as disease-modifiers in neurodegenerative diseases.

Biliary acids may influence each of the following three mechanisms through which interactions within the brain-gut-microbiota axis take place: neurological, immunological, and neuroendocrine. These microbial metabolites can act as direct neurotransmitters or neuromodulators, serving as key modulators of the brain-gut interactions.

The gut microbial community, through their capacity to produce bile acid metabolites distinct from the liver, can be thought of as an endocrine organ with potential to alter host physiology, perhaps to their own favour. Hydrophilic bile acids, currently regarded as important hormones, exert modulatory effects on gut microbiota composition to produce secondary bile acids which seem to bind a number of receptors with a higher affinity than primary biliary acids, expressed on many different cells.


TUDCA regulates expression of genes involved in cell cycle regulation and apoptotic pathways, promoting neuronal survival. TUDCA:

  • Improves protein folding capacity through its chaperoning activity, in turn reducing protein aggregation and deposition;
  • Reduces reactive oxygen species production, leading to protection against mitochondrial dysfunction;
  • Ameliorates endoplasmic reticulum stress; and
  • Inhibits expression of pro-inflammatory cytokines, exerting an anti-neuroinflammatory effect.

Although Alzheimer’s disease, Huntington’s disease, Parkinson’s disease, amyotrophic lateral sclerosis (ALS), and cerebral ischemia have different disease progressions, they share similar pathways which can be targeted by TUDCA. This makes this bile acid a potentially strong therapeutic option to be tested in human diseases. Clinical evidence collected so far has reported comprehensive data on ALS only.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9166453/ “Tauroursodeoxycholic acid: a potential therapeutic tool in neurodegenerative diseases”

The misnomer of nonessential amino acids

Three papers, starting with a 2022 review:

“Ideal diets must provide all physiologically and nutritionally essential amino acids (AAs).

Proposed optimal ratios and amounts of true digestible AAs in diets during different phases of growth and production. Because dynamic requirements of animals for dietary AAs are influenced by a plethora of factors, data below as well as the literature serve only as references to guide feeding practices and nutritional research.


Nutritionists should move beyond the ‘ideal protein’ concept to consider optimum ratios and amounts of all proteinogenic AAs in diets for mammals, birds, and aquatic animals, and, in the case of carnivores, also taurine. This will help formulate effectively low-protein diets for livestock (including swine and high-producing dairy cattle), poultry, fish, and crustaceans, as well as zoo and companion animals.”

https://journals.sagepub.com/doi/10.1177/15353702221082658 “The ‘ideal protein’ concept is not ideal in animal nutrition”

A second 2022 review focused on serine:

“The main dietary source of L-serine is protein, in which L-serine content ranges between 2 and 5%. At the daily intake of ~1 g protein per kg of body weight, the amount of serine obtained from food ranges between 1.4 and 3.5 g (13.2–33.0 mmol) per day in an adult.

Mechanisms of potential benefits of supplementing L-serine include increased synthesis of sphingolipids, decreased synthesis of 1-deoxysphingolipids, decrease in homocysteine levels, and increased synthesis of cysteine and its metabolites, including glutathione. L-serine supplementation has been suggested as a rational therapeutic approach in several disorders, particularly primary disorders of L-serine synthesis, neurodegenerative disorders, and diabetic neuropathy.

Unfortunately, the number of clinical studies evaluating dietary supplementation of L-serine as a possible therapy is small. Studies examining therapeutic effects of L-serine in CNS injury and chronic renal diseases, in which it is supposed that L-serine weakens glutamate neurotoxicity and lowers homocysteine levels, respectively, are missing.”

https://www.mdpi.com/2072-6643/14/9/1987/htm “Serine Metabolism in Health and Disease and as a Conditionally Essential Amino Acid”

A 2021 review subject was D-serine, L-serine’s D-isoform:

“The N-methyl-D-aspartate glutamate receptor (NMDAR) and its co-agonist D-serine are currently of great interest as potential important contributors to cognitive function in normal aging and dementia. D-serine is necessary for activation of NMDAR and in maintenance of long-term potentiation, and is involved in brain development, neuronal connectivity, synaptic plasticity, and regulation of learning and memory.

The source of D-amino acids in mammals was historically attributed to diet or intestinal bacteria until racemization of L-serine by serine racemase was identified as the endogenous source of D-serine. The enzyme responsible for catabolism (breakdown) of D-serine is D-amino acid oxidase; this enzyme is most abundant in cerebellum and brainstem, areas with low levels of D-serine.

Activation of the NMDAR co-agonist-binding site by D-serine and glycine is mandatory for induction of synaptic plasticity. D-serine acts primarily at synaptic NMDARs whereas glycine acts primarily at extrasynaptic NMDARs.

In normal aging there is decreased expression of serine racemase and decreased levels of D-serine and down-regulation of NMDARs, resulting in impaired synaptic plasticity and deficits in learning and memory. In contrast, in AD there appears to be activation of serine racemase, increased levels of D-serine and overstimulation of NMDARs, resulting in cytotoxicity, synaptic deficits, and dementia.”

https://www.frontiersin.org/articles/10.3389/fpsyt.2021.754032/full “An Overview of the Involvement of D-Serine in Cognitive Impairment in Normal Aging and Dementia”


Brain changes

This 2022 human study investigated healthy young adult brain changes using MRI and epigenetic clock technologies:

“We aimed to characterize the association of epigenetic age (i.e. estimated DNA methylation age) and its acceleration with surface area, cortical thickness, and volume in healthy young adults. It is largely unknown how accelerated epigenetic age affects multiple cortical features among young adults from 19 to 49 years. Prior findings imply not only that these dynamic changes reveal different aspects of cortical aging, but also that chronological age itself is not a reliable factor to understand the process of cortical aging.

accelerated epigenetic age vs brain features

Seventy-nine young healthy individuals participated in this study. Findings of our study should be interpreted within the context of relatively small sample size, without older adults, and with epigenetic age assessed from saliva.

Additional and unique regional changes due to advanced and accelerated epigenetic age, compared to chronological age-related changes, suggest that epigenetic age could be a viable biomarker of cortical aging. Longitudinal and cross-sectional studies with a larger sample and wider age range are necessary to characterize ongoing effects of epigenetic cortical aging, not only for healthy but also for pathological aging.”

https://doi.org/10.1093/cercor/bhac043 “The effects of epigenetic age and its acceleration on surface area, cortical thickness, and volume in young adults” (not freely available) Thanks to Dr. Yong Jeon Cheong for providing a copy.

Thyroid function

This 2022 review subject was thyroid function changes:

“Circulating concentrations of thyrotropin (TSH) and thyroxine (T4) are tightly regulated. Each individual has setpoints for TSH and free T4 which are genetically determined, and subject to environmental and epigenetic influence.

What is normal for one individual may not be normal for another, even within conventional definitions of euthyroidism. Notably, circulating TSH exists in several different isoforms with varying degrees of glycosylation, sialylation, and sulfonation which affect tissue availability and bioactivity. This is not reflected in immunoreactive TSH concentrations determined by routine laboratory assays.


TSH and free T4 relationship analyzed by age in 120,403 patients who were not taking thyroxine treatment. Median TSH for each free T4 integer value (in pmol/ L) was calculated, then plotted as 20-year age bands in adults. Dotted horizontal and vertical lines mark the TSH reference range (0.4 to 4.0 mU/L) and free T4 reference range (10 to 20 pmol/L), respectively.

Mild TSH elevation in older people does not predict adverse health outcomes. In fact, higher TSH is associated with greater life expectancy, including extreme longevity.

In older people, TSH increases with aging without an accompanying fall in free T4. Clinical guidelines now recommend against routine levothyroxine treatment in older people with mild subclinical hypothyroidism.”

https://e-enm.org/journal/view.php?doi=10.3803/EnM.2022.1463 “Thyroid Function across the Lifespan: Do Age-Related Changes Matter?”


Lifespan Uber Correlation

This 2022 study developed new epigenetic clocks:

“Maximum lifespan is deemed to be a stable trait in species. The rate of biological function decline (i.e., aging) would be expected to correlate inversely with maximum species lifespan. Although aging and maximum lifespan are intimately intertwined, they nevertheless appear in some investigations to be distinct processes.

Some cytosines conserved across mammals exhibit age-related methylation changes so consistent that they were used to successfully develop cross-species age predictors. In a similar vein, methylation levels of some conserved cytosines correlate highly with species lifespan, leading to the development of highly accurate lifespan predictors. Surprisingly, little to no commonality is found between these two sets of cytosines.

We correlated the intra-species age correlation with maximum lifespan across mammalian species. We refer to this correlation of correlations as Lifespan Uber Correlation (LUC).

We overlapped genes from the LUC signature with genes found in human genome-wide association studies (GWAS) of various pathologies and conditions. With all due caution, we report that some genes from the LUC signature were those highlighted by GWAS to be associated with type II diabetes, stroke, chronic kidney disease, and breast cancer.

Human aging genes vs mammalian LUC

We used the subset of CpGs found to be significant in our LUC to build age estimators (epigenetic clocks). We demonstrated that these clocks are able to capture effects of interventions that are known to alter age as well as lifespan, such as caloric restriction, growth hormone receptor knockout, and high-fat diet.

We found that Bcl11b heterozygous knockout mice exhibited an increased epigenetic age in the striatum. BCL11B is a zinc finger protein with a wide range of functions, including development of the brain, immune system, and cardiac system.

This gene is also implicated in several human diseases including, but not limited to, Huntington disease, Alzheimer’s diseases, HIV, and T-cell malignancies. BCL11B plays an important role in adult neurogenesis, but is less studied in the context of lifespan disparities in mammals.

Bcl11b knockout affected both DNA methylation and mRNA expression of LUC genes. Our current study does not inform us about the potential role of Bcl11b in aging processes during adulthood since observed patterns could be attributed to developmental defects.

We are characterizing other genetic and non-genetic interventions that perturb the LUC clocks. These we will feature in a separate report that will uncover biological processes regulated by LUC cytosines and their associated genes.”

https://www.biorxiv.org/content/10.1101/2022.01.16.476530v1 “Divergent age-related methylation patterns in long and short-lived mammals”


Defend yourself with taurine

This densely packed 2021 review subject was taurine:

“Taurine (Tau), a sulphur-containing non-proteinogenic β-amino acid, has a special place as an important natural modulator of antioxidant defence networks:

  • Direct antioxidant effect of Tau due to scavenging free radicals is limited, and could be expected only in a few tissues (heart and eye) with comparatively high concentrations.
  • Maintaining optimal Tau status of mitochondria controls free radical production.
  • Indirect antioxidant activities of Tau due to modulating transcription factors leading to upregulation of the antioxidant defence network are likely to be major molecular mechanisms of Tau’s antioxidant and anti-inflammatory activities.
  • A range of toxicological models clearly show protective antioxidant-related effects of Tau.”


https://www.mdpi.com/2076-3921/10/12/1876/htm “Taurine as a Natural Antioxidant: From Direct Antioxidant Effects to Protective Action in Various Toxicological Models”


Inevitable individual differences

This 2021 review subject was individual differences:

“We will focus on recent findings that try to shed light on the emergence of individuality, with a particular interest in Drosophila melanogaster.


Another possible source of potential behavioral variability might come from the interaction of individuals with environmental microbes, from Wolbachia infections to changes in the gut microbiome. In this particular case, no genetic variation or neural circuit alteration would be responsible for the change in behavior.

Finally, from an evolutionary point of view, individuality might play an essential role in providing an adaptive advantage. For example, we have described that animals might use diversified bet-hedging as a mechanism to produce high levels of variation within a population to ensure that at least some individuals will be well-adapted when facing unpredictable environments.”

https://www.frontiersin.org/articles/10.3389/fphys.2021.719038/full “Behavior Individuality: A Focus on Drosophila melanogaster

Other papers on this subject include:


Offspring brain effects from maternal adversity

This 2021 rodent study investigated conception through weaning effects on offspring from stressing their mothers:

“We investigated consequences of two prenatal insults, prenatal alcohol exposure (PAE) and food-related stress, on DNA methylation profiles of the rat brain during early development. We analyzed patterns in prefrontal cortex, a key brain region involved in cognition, executive function, and behavior, of both males and females, and found sex-dependent and sex-concordant influences of these insults.

The pair-fed (PF) group in the PAE model is a standard control for effects of alcohol in reducing food intake. However, compared to the PAE group that, albeit eating less, eats ad libitum, pair-feeding is a treatment in itself, with PF dams receiving a restricted ration, which results in both hunger and a disrupted feeding schedule. These stress-related effects could potentially parallel or model food scarcity or food insecurity in human populations.

We observed more DMRs (Differentially Methylated Regions) that showed decreased DNAm rather than increased DNAm in PF animals, suggesting that food-related stress may interfere with one-carbon metabolism and the pathways that deposit methylation on DNA. We also identified a sex-concordant DMR that showed decreased DNAm in PF animals in the glucocorticoid receptor Nr3c1, which plays a key role in stress responsivity and may reflect a reprogramming of the stress response.

This result is in line with previous studies that have shown that pair-feeding is a considerable stressor on dams, with lasting consequences on development, behavior, and physiology of their offspring. Altered DNAm of this key HPA axis gene may reflect broader alterations to stress response systems, which may in turn, influence programming of numerous physiological systems linked to the stress response, including immune function, metabolic processes, and circadian rhythms.

In PAE and PF animals compared to controls, we identified 26 biological pathways that were enriched in females, including those involved in cellular stress and metabolism, and 10 biological pathways enriched in males, which were mainly involved in metabolic processes. These findings suggest that PAE and restricted feeding, both of which act in many respects as prenatal stressors, may influence some common biological pathways, which may explain some of the occasional overlap between their resulting phenotypes.


This study highlights the complex network of neurobiological pathways that respond to prenatal adversity/stressors and that modulate differential effects of early life insults on functional and health outcomes. Study of these exposures provides a unique opportunity to investigate sex-specific effects of prenatal adversity on epigenetic patterns, as possible biological mechanisms underlying sex-specific responses to prenatal insults are understudied and remain largely unknown.”

https://www.mdpi.com/2073-4425/12/11/1773/htm “Prenatal Adversity Alters the Epigenetic Profile of the Prefrontal Cortex: Sexually Dimorphic Effects of Prenatal Alcohol Exposure and Food-Related Stress”


Reworking evolutionary theory

Dr. Michael Skinner coauthored a 2021 review arguing for inclusion of epigenetic transgenerational inheritance into evolutionary theory:

“Over the past 50 years, molecular technology has been used to investigate evolutionary biology. Many examples of finding no correlated genetic mutations or a low frequency of DNA sequence mutations suggest that additional mechanisms are also involved.

  • Identical twins have essentially the same genetics, but generally develop discordant disease as they age.
  • Only a low frequency (generally 1% or less) of individuals that have a specific disease have a correlated genetic mutation.
  • Dramatic increases in disease frequency in the population cannot be explained with genetics alone.

DNA methylation, histone modifications, changes to chromatin structure, expression of non-coding RNA, and RNA methylation can directly regulate gene expression independent of DNA sequence. These different epigenetic factors do not only act independently, but integrate with each other to provide a level of epigenetic complexity to accommodate the needs of cellular development and differentiation.


Environmental epigenetics is the primary molecular mechanism in any organism that is used to promote physiological and phenotypic alterations. Actions of environmental factors early in development can permanently program the cellular molecular function, which then impacts later life disease or phenotypes.


Integration of epigenetics and genetics contribute to a Unified Theory of Evolution that explains environmental impacts, phenotypic variation, genetic variation, and adaptation that natural selection acts on. The current review expands this proposed concept and provides a significant amount of supporting literature and experimental models to support the role of environmentally induced epigenetic transgenerational inheritance in evolution.”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8557805/ “Role of environmentally induced epigenetic transgenerational inheritance in evolutionary biology: Unified Evolution Theory”

Organisms cited in this review’s references are similar to humans in ancestral influences and developmental influences during the first 1000 days of our lives. Humans are different in that even after all these influences, we can choose to influence our own change and individually evolve. We can also change our internal environments per Switch on your Nrf2 signaling pathway and An environmental signaling paradigm of aging.


Do genes determine monogamy / polygamy?

This 2021 rodent study developed epigenetic clocks for deer mice:

“We have undertaken a genome-wide analysis of DNA methylation in Peromyscus, spanning different species, stocks, sexes, tissues, and age cohorts. We present CpGs and enriched pathways that relate to different conditions such as chronological age, high altitude, and monogamous behavior.

  • Analysis involved tails, whole brain, and liver samples that are not major target tissues for sex hormones. This implies that sex-specific patterns of methylation are inflicted early during development, and persist at adulthood.
  • Altitude-specific age-related changes are adjacent to genes that play a role in brain development, immune system functioning, and T-cell development.
  • Comparison of brain specimens between older P. leucopus and P. maniculatus indicated that in the latter, coordination of the unfolded protein response is compromised, and evidence of neurodegenerative pathology was obtained.
  • Our study involved three monogamous (P. californicus, P. polionotus, and P. eremicus) and two polygamous (P. maniculatus and P. leucopus) species. The most significant EWAS hits for monogamy included decreased methylation in Zeb2 intron, a key regulator of midbrain dopaminergic neuron development. These results derived from tail tissues, suggesting that inherent differences in bonding behavior instruct specific epigenetic changes in peripheral tissues that may be translated into distinct physiological outcomes. Whether this is due to differential regulation of specific neurohormonal circuits in response to hormones and neurotransmitters related to bonding, and what the exact physiological outputs are, remains to be determined.

Our study provided the first epigenetic clock for Peromyscus, and illustrated the hierarchical association between various biological variables in determining methylation profiles across different scales of biological organization.”

https://link.springer.com/article/10.1007/s11357-021-00472-5 “Methylation studies in Peromyscus: aging, altitude adaptation, and monogamy”


All about the betaine, Part 2

Continuing Part 1 by curating a partial outline of a 2021 review:

“This review focuses on the biological and beneficial effects of dietary betaine (trimethylglycine), a naturally occurring and crucial methyl donor.

Betaine has a neuroprotective role, preserves myocardial function, and prevents pancreatic steatosis. Betaine also attenuates oxidant stress, endoplasmic reticulum stress, inflammation, and cancer development.

  • Betaine Protects against Development of Alcohol-Induced Hepatic Steatosis
  • Betaine Protects against Detrimental Effects of HCV and Ethanol on Innate Immunity
  • Betaine Maintains Intestinal Epithelial Barrier Integrity
  • Betaine Maintains Adipose Function


Human intervention studies showed no adverse effects with 4 g/day supplemental administration of betaine in healthy subjects. However, overweight subjects with metabolic syndrome showed a significant increase in total and LDL-cholesterol concentrations. These effects were not observed with 3 g/day of betaine administration.

We suggest betaine as a promising therapeutic for clinical use to treat these aforementioned diseases as well as other liver-/non-liver-related diseases and conditions.”

https://www.mdpi.com/2079-7737/10/6/456/htm “Beneficial Effects of Betaine: A Comprehensive Review”

This review cited a 2020 study Transgenerational Inheritance of Betaine-Induced Epigenetic Alterations in Estrogen-Responsive IGF-2/IGFBP2 Genes in Rat Hippocampus (not freely available):

“Hippocampal expression of aromatase, estrogen receptor α, and estrogen-related receptor β is downregulated in F1, together with estrogen-responsive insulin-like growth factor 2/insulin-like growth factor binding protein 2 (IGF-2/IGFBP2) genes. However, all these genes are upregulated in F2, which follows the same pattern of F0.

Imprinting control region of IGF-2 gene is hypomethylated in F1 but hypermethylated in F2 and F0. In contrast, the promoter DNA methylation status of all affected genes is hypermethylated in F1 but hypomethylated in F2 and F0.”

  • Intergenerational flip-flops of F0 phenotypes to opposite F1 phenotypes back to F0 phenotypes in the F2 generation can’t conclusively demonstrate transgenerational epigenetic inheritance of alterations due to betaine consumption during pregnancy.
  • Those researchers had to continue on to a F3 female generation for transgenerational results, because F2 generation cells were present in F1 fetuses, and were potentially affected during pregnant F0 treatments.

I came across this paper through a citation chain initiated by Dr. Paul Clayton’s blog post Foie Gras:

“Thanks to our modern diet and lifestyle, nonalcoholic fatty liver disease (NAFLD) is now reckoned to affect an astonishing quarter of the world’s population.”


Epigenetic clocks so far in 2021

2021’s busiest researcher took time out this month to update progress on epigenetic clocks:

Hallmarks of aging aren’t all associated with epigenetic aging.

epigenetic aging vs. hallmarks of aging

Interventions that increase cellular lifespan aren’t all associated with epigenetic aging.

epigenetic aging vs. cellular lifespan

Many of his authored or coauthored 2021 papers developed human / mammalian species relative-age epigenetic clocks.

epigenetic clock mammalian maximum lifespan

Relative-age epigenetic clocks better predict human results from animal testing.

pan-mammalian epigenetic clock

Previously curated papers that were mentioned or relevant included:

All about vasopressin

This 2021 review subject was vasopressin:

“Vasopressin is a ubiquitous molecule playing an important role in a wide range of physiological processes, thereby implicated in pathomechanisms of many disorders. The most striking is its central effect in stress-axis regulation, as well as regulating many aspects of our behavior.

Arginine-vasopressin (AVP) is a nonapeptide that is synthesized mainly in the supraoptic, paraventricular (PVN), and suprachiasmatic nucleus of the hypothalamus. AVP cell groups of hypothalamus and midbrain were found to be glutamatergic, whereas those in regions derived from cerebral nuclei were mainly GABAergic.

In the PVN, AVP can be found together with corticotropin-releasing hormone (CRH), the main hypothalamic regulator of the HPA axis. The AVPergic system participates in regulation of several physiological processes, from stress hormone release through memory formation, thermo- and pain regulation, to social behavior.

vasopressin stress axis

AVP determines behavioral responses to environmental stimuli, and participates in development of social interactions, aggression, reproduction, parental behavior, and belonging. Alterations in AVPergic tone may be implicated in pathology of stress-related disorders (anxiety and depression), Alzheimer’s, posttraumatic stress disorder, as well as schizophrenia.

An increasing body of evidence confirms epigenetic contribution to changes in AVP or AVP receptor mRNA level, not only during the early perinatal period, but also in adulthood:

  • DNA methylation is more targeted on a single gene; and it is better characterized in relation to AVP;
  • Some hint for bidirectional interaction with histone acetylation was also described; and
  • miRNAs are implicated in the hormonal, peripheral role of AVP, and less is known about their interaction regarding behavioral alteration.”

https://www.mdpi.com/1422-0067/22/17/9415/htm “Epigenetic Modulation of Vasopressin Expression in Health and Disease”

Find your way, regardless of what the herd does.


Take taurine for your mitochondria

This 2021 review summarized taurine’s beneficial effects on mitochondrial function:

“Taurine supplementation protects against pathologies associated with mitochondrial defects, such as aging, mitochondrial diseases, metabolic syndrome, cancer, cardiovascular diseases and neurological disorders. Potential mechanisms by which taurine exerts its antioxidant activity in maintaining mitochondria health include:

  1. Conjugates with uridine on mitochondrial tRNA to form a 5-taurinomethyluridine for proper synthesis of mitochondrial proteins (mechanism 1), which regulates the stability and functionality of respiratory chain complexes;
  2. Reduces superoxide generation by enhancing the activity of intracellular antioxidants (mechanism 2);
  3. Prevents calcium overload and prevents reduction in energy production and collapse of mitochondrial membrane potential (mechanism 3);
  4. Directly scavenges HOCl to form N-chlorotaurine in inhibiting a pro-inflammatory response (mechanism 4); and
  5. Inhibits mitochondria-mediated apoptosis by preventing caspase activation or by restoring the Bax/Bcl-2 ratio and preventing Bax translocation to the mitochondria to promote apoptosis.

taurine mechanisms

An analysis on pharmacokinetics of oral supplementation (4 g) in 8 healthy adults showed a baseline taurine content in a range of 30 μmol to 60 μmol. Plasma content increased to approximately 500 μmol 1.5 h after taurine intake. Plasma content subsequently decreased to baseline level 6.5 h after intake.

We discuss antioxidant action of taurine, particularly in relation to maintenance of mitochondria function. We describe human studies on taurine supplementation in several mitochondria-associated pathologies.”

https://www.mdpi.com/1420-3049/26/16/4913/html “The Role of Taurine in Mitochondria Health: More Than Just an Antioxidant”

I take a gram of taurine at breakfast and at dinner along with other supplements and 3-day-old Avena sativa oat sprouts. Don’t think my other foods’ combined taurine contents are more than one gram, because none are found in various top ten taurine-containing food lists.

As a reminder, your mitochondria came from your mother, except in rare cases.

Preventing human infections with dietary fibers

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