Gut and brain health

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.


PXL_20210628_095746132

Wildlife

PXL_20210710_100826663

Take acetyl-L-carnitine for early-life trauma

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”


Previously curated studies cited were:

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.


PXL_20210704_095621886

One aspect of research on short-chain fatty acids

To further understand An overlooked gut microbiota product, a 2018 rodent study found:

“Microbial metabolites short-chain fatty acids (SCFAs) have been implicated in gastrointestinal functional, neuroimmune regulation, and host metabolism, but their role in stress-induced behavioural and physiological alterations is poorly understood

SCFAs are primarily derived from fermentation of dietary fibres, and play a pivotal role in host gut, metabolic and immune function. All these factors have previously been demonstrated to be adversely affected by stress.

Administration of SCFAs to mice undergoing psychosocial stress alleviated enduring alterations in anhedonia and heightened stress-responsiveness, as well as stress-induced increases in intestinal permeability.

experimental design

SCFA treatment alleviated psychosocial stress-induced alterations in reward-seeking behaviour, and increased responsiveness to an acute stressor and in vivo intestinal permeability. In addition, SCFAs exhibited behavioural test-specific antidepressant and anxiolytic effects, which were not present when mice had also undergone psychosocial stress.”

https://physoc.onlinelibrary.wiley.com/doi/pdf/10.1113/JP276431 “Short-chain fatty acids: microbial metabolites that alleviate stress-induced brain–gut axis alterations”


One way researchers advance science is to relate aspects of their findings to previous studies. That approach works, but may miss items that weren’t covered in previous research.

This study fed specific quantities of three SCFAs – acetate, butyrate, and propionate – apparently due to previous research findings. If other SCFAs produced by gut microbiota were ignored – like crotonate (aka unsaturated butyrate) – how would that approach advance science?

I found this study from its citation in Harnessing endogenous defenses with broccoli sprouts.

Several diseases, one treatment?

This 2021 review summarized three dietary supplements’ effects on psychiatric symptoms:

“Upregulation of Nrf2 has been suggested as a common therapeutic target for major neuropsychiatric disorders. In this paper, evidence is presented showing how NAC [N-acetyl-cysteine], coenzyme Q10 (CoQ), and melatonin can ameliorate many important effects of oxidative stress by upregulating Nrf2.

Given its key role in governing cellular antioxidant response, upregulation of Nrf2 has been suggested as a common therapeutic target in neuropsychiatric illnesses such as major depressive disorder, bipolar disorder, and schizophrenia. These are associated with chronic oxidative and nitrosative stress, characterised by elevated levels of reactive oxygen species, nitric oxide, and peroxynitrite.

CoQ:

  • Acts as a superoxide scavenger in neuroglial mitochondria;
  • Instigates mitohormesis;
  • Ameliorates lipid peroxidation in the inner mitochondrial membrane;
  • Activates uncoupling proteins;
  • Promotes mitochondrial biogenesis; and
  • Has positive effects on the plasma membrane redox system.

Melatonin:

  • Scavenges mitochondrial free radicals;
  • Inhibits mitochondrial nitric oxidesynthase;
  • Restores mitochondrial calcium homeostasis;
  • Deacetylates and activates mitochondrial SIRT3;
  • Ameliorates increased permeability of the blood-brain barrier and intestine; and
  • Counters neuroinflammation and glutamate excitotoxicity.”

https://www.researchgate.net/publication/348309816_Increasing_Nrf2_Activity_as_a_Treatment_Approach_in_Neuropsychiatry “Increasing Nrf2 Activity as a Treatment Approach in Neuropsychiatry” (registration required)


These reviewers explored three selected supplements, citing 380 references. They overlooked something, though. There was only one mention of sulforaphane in their paper, yet four references’ titles included sulforaphane?

I take two of the three exogenous supplements discussed. The one I stopped taking over a year ago – NAC – was thoroughly discussed, but not in contexts directly related to the Nrf2 transcription factor. Why?

Switch on your Nrf2 signaling pathway pointed out:

“We use NAC in the lab all the time because it stops an Nrf2 activation. So that weak pro-oxidant signal that activates Nrf2, you switch it off by giving a dose of NAC. It’s a potent antioxidant in that right, but it’s blocking signalling. And that’s what I don’t like about its broad use.”

The current review noted that Nrf2 is activated by oxidative stress. NAC is a precursor to glutathione – our main endogenous antioxidant – and neither one activates Nrf2 pathways.

What does? Sulforaphane.

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Don’t brew oat sprouts – eat them!

This 2020 study chemically analyzed four grains and their brew-processing products:

“Side-stream products of malting, particularly rootlet, are currently treated as animal feed. Instead of ending up in final products (e.g., malt and beer), a substantial portion of phytochemicals end up in side streams.

Rootlets are being increasingly investigated to overcome their bitter taste and to unleash their potential. Adding the fact that side-stream products produced in high quantity are also rich in protein, their nutritional value may be too high to justify usage as feed rather than food.

Grains were steeped for 26 to 30 h with a wet–dry–wet steeping program. Oats were wet steeped for 4 h at 13 °C before and after 18 h of dry steeping at 15 °C.

All grains were germinated for 6 days at 15 °C, after which they were dried with a gentle kilning program to a final temperature of 83 °C and moisture of 4%. Rootlets were separated from malt after drying.

Statistically significant changes occurred in abundance of all 285 annotated phytochemicals during malting, when comparing whole grain with malted grain or rootlet. In oats, cumulative levels of avenanthramides increased by 2.6-fold in the malted grain compared to intact whole grain. Up to 25-fold increase has been reported previously after a slightly longer germination.

Phenolamides cumulative levels in oats increased in both malted grain (11-fold) and rootlet (50-fold). Cumulative flavonoid levels were nearly 3-fold higher in malted grain and rootlet compared to whole grain.

Avenanthramides and phenolamides had much lower extractability into the water extract and wort.

To our knowledge, this is the first time avenanthramides are reported from any other species than oats, suggesting that the synthesis pathway for avenanthramides evolved before oats diverged from the other cereals. Furthermore, benzoxazinoids are herein reported for the first time in oats.

Several previously uncharacterized saponins were found in oats in addition to the previously known avenacins and avenacosides. However, because of limited reference data currently available, their identity could not be determined beyond compound class and molecular formula in this study.

Plants can synthetize up to hundreds of thousands of secondary metabolites, and current spectral databases only contain a fraction of them to allow identification. Compounds found in this study do not represent the complete range of phytochemicals existing in cereals.”

https://www.nature.com/articles/s41538-020-00081-0 “Side-stream products of malting: a neglected source of phytochemicals”


Twice a day for six weeks I’ve eaten oat sprouts 3-to-6-days old from two species and three varieties. I’ve never noticed any “bitter taste” of rootlets mentioned.

Maybe “a final temperature of 83 °C and moisture of 4%” had something to do with it? Oat sprouts I ate never got above 25°C, and I doubt their moisture content was < 80%.

Maybe “Oats were wet steeped for 4 h at 13 °C before and after 18 h of dry steeping at 15 °C” gave oat sprouts a bitter taste? I process oat sprout batches the same way I do broccoli sprout batches. A new batch soaks to start germination every 12 hours, then is rinsed three times every 24 hours on a 6 hours – 6 hours – 12 hours cycle. Temperature in my kitchen is 21°C (70°F) because it’s winter outside.

The above graphic is a heat map of 29 studied C-type avenanthramides. Don’t know why 26 known A-type avenanthramides described in Eat oats today! weren’t analyzed. The second study of Sprouting oats stated:

“There is a higher concentration of A-type AVAs [avenanthramides] than C-type AVAs in sprouted oats.”

Reference 33’s “up to 25-fold increase” is curated in Eat oat sprouts for AVAs.

Gut microbiota and aging

This 2020 review explored the title subject:

“The human body contains 1013 human cells and 1014 commensal microbiota. Gut microbiota play vital roles in human development, physiology, immunity, and nutrition.

Human lifespan was thought to be determined by the combined influence of genetic, epigenetic, and environmental factors including lifestyle-associated factors such as exercise or diet. The role of symbiotic microorganisms has been ignored.

Age-associated alterations in composition, diversity, and functional features of gut microbiota are closely correlated with an age-related decline in immune system functioning (immunosenescence) and low-grade chronic inflammation (inflammaging). Immunosenescence and inflammaging do not have a unidirectional relationship. They exist in a mutually maintained state where immunosenescence is induced by inflammaging and vice versa.

Immunosenescence changes result in both quantitative and qualitative modifications of specific cellular subpopulations such as T cells, macrophages and natural killer cells as opposed to a global deterioration of the immune system. Neutrophils and macrophages from aged hosts are less active with diminished phagocytosing capability.

Gut microbiota transform environmental signals and dietary molecules into signaling metabolites to communicate with different organs and tissues in the host, mediating inflammation. Gut microbiota modulations via dietary or probiotics are useful anti-inflammaging and immunosenescence interventions.

The presence of microbiomic clocks in the human body makes noninvasive, accurate lifespan prediction possible. Prior to occurrence of aging-related diseases [shown above], bidirectional interactions between the gut and extraenteric tissue will change.

Correction of accelerated aging-associated gut dysbiosis is beneficial, suggesting a link between aging and gut microbiota that provides a rationale for microbiota-targeted interventions against age-related diseases. However, it is still unclear whether gut microbiota alterations are the cause or consequence of aging, and when and how to modulate gut microbiota to have anti-aging effects remain to be determined.”

https://www.tandfonline.com/doi/abs/10.1080/10408398.2020.1867054 “Gut microbiota and aging” (not freely available; thanks to Dr. Zongxin Ling for providing a copy)


1. The “Stable phase” predecessor to this review’s subject deserved its own paper:

“After initial exposure and critical transitional windows within 3 years after birth, it is generally agreed that human gut microbiota develops into the typical adult structure and composition that is relatively stable in adults.

gut microbiota by age phenotype

However, the Human Microbiome Project revealed that various factors such as food modernization, vaccines, antibiotics, and taking extreme hygiene measures will reduce human exposure to microbial symbionts and led to shrinkage of the core microbiome, while the reduction in microbiome biodiversity can compromise the human immune system and predispose individuals to several modern diseases.”

2. I looked for the ten germ-free references in the “How germ-free animals help elucidate the mechanisms” section of The gut microbiome: its role in brain health in this review, but didn’t find them cited. Likewise, the five germ-free references in this review weren’t cited in that paper. Good to see a variety of relevant research.

There were a few overlapping research groups with this review’s “Gut-brain axis aging” section, although it covered only AD and PD research.

3. Inflammaging is well-documented, but is chronic inflammation a condition of chronological age?

A twenty-something today who ate highly-processed food all their life could have gut microbiota roughly equivalent to their great-great grandparents’ at advanced ages. Except their ancestors’ conditions may have been byproducts of “an unintended consequence of both developmental programmes and maintenance programmes.

Would gut microbiota be a measure of such a twenty-something’s biological age? Do we wait until they’re 60, and explain their conditions by demographics? What could they do to reset themself back to a chronological-age-appropriate phenotype?


The future of your brain is in your gut right now

A 2020 paper by the author of Sulforaphane: Its “Coming of Age” as a Clinically Relevant Nutraceutical in the Prevention and Treatment of Chronic Disease:

“The gut and brain communicate bidirectionally via several pathways which include:

  1. Neural via the vagus nerve;
  2. Endocrine via the HPA axis;
  3. Neurotransmitters, some of which are synthesized by microbes;
  4. Immune via cytokines; and
  5. Metabolic via microbially generated short-chain fatty acids.

How does nature maintain the gut-microbiome-brain axis? Mechanisms to maintain homeostasis of intestinal epithelial cells and their underlying cells are a key consideration.

The symbiotic relationship that exists between microbiota and the human host is evident when considering nutrient requirements of each. The host provides food for microbes, which consume that food to produce metabolites necessary for health of the host.

Consider function of the human nervous system, not in isolation but in integration with the gastrointestinal ecosystem of the host, in expectation of a favorable impact on human health and behavior.”

https://www.sciencedirect.com/science/article/pii/B9780128205938000148 “Chapter 14 – The gut microbiome: its role in brain health” (not freely available)


Always more questions:

  1. What did you put into your gut today?
  2. What type of internal environment did it support?
  3. What “favorable impact on human health and behavior” do you expect from today’s intake?
  4. How will you feel?
  5. Will you let evidence guide feeding your gut environment?

See Harnessing endogenous defenses with broccoli sprouts for further elaboration. See Switch on your Nrf2 signaling pathway for an interview with these papers’ author.

Week 37 of Changing to a youthful phenotype with broccoli sprouts

1. Been wrong about a few things this past week:

A. I thought in Week 28 that extrapolating A rejuvenation therapy and sulforaphane results to humans would produce personal results by this week. An 8-day rat treatment period ≈ 258 human days, and 258 / 7 ≈ 37 weeks.

There are just too many unknowns to say why that didn’t happen. So I’ll patiently continue eating a clinically relevant 65.5 gram dose of microwaved broccoli sprouts twice every day.

PXL_20201015_105645362

The study’s lead researcher answered:

“Depends, it might take 37 weeks or more for some aspects of ‘youthening’ to become obvious. It might even take years for others.

Who really cares if you are growing younger every day?

For change at the epigenomic/cellular level to travel up the biological hierarchy from cells to organ systems seems to take time. But the process can be repeated indefinitely (so far as we know) so by the second rejuvenation you’re already starting at ‘young’. (That would be every eight to ten years I believe.)”

His framework is in An environmental signaling paradigm of aging.

B. I thought that adding 2% mustard seed powder to microwaved broccoli sprouts per Does sulforaphane reach the colon? would work. Maybe it would, maybe it wouldn’t, but my stomach and gut said that wasn’t for me.

C. I thought I could easily add Sprouting whole oats to my routine. I ran another trial Sprouting hulled oats using oat seeds from a different company and Degree of oat sprouting as a model.

2. Oat sprouts analysis paired studies were very informative, don’t you think? One study produced evidence over 18 germination-parameter combinations (hulled / dehulled seeds of two varieties, for 1-to-9 days, at 12-to-20°C).

Those researchers evaluated what mix of germination parameters would simultaneously maximize four parameters (β-glucan, free phenolic compounds, protease activity, and antioxidant capacity) while minimizing two (enzymes α-amylase and lipase). Then they followed with a study that characterized oat seeds sprouted under these optimal conditions.

I doubted PubMed’s “oat sprout” 20 search results for research 1977 to the present. Don’t know why they didn’t pick up both of these 2020 studies, but I’m sure that .gov obvious hindrances to obtaining relevant information like this won’t be fixed. What other search terms won’t return adequate PubMed results?

3. The blog post readers viewed this week that I made even better was Do delusions have therapeutic value? from May 2019. Sometimes I’ve done good posts describing why papers are poorly researched.

4. I’ve often changed my Week 4 recipe for an AGE-less Chicken Vegetable Soup dinner (half) then the next day for lunch. The biggest change brought about by 33 weeks of behavioral contagion is that I now care more about whether vegetables are available than whether or not they’re organic. Coincidentally, I’ve developed a Costco addiction that may require intervention.

  • 1/2 lemon
  • 4 Roma tomatoes
  • 4 large carrots
  • 6 stalks organic celery
  • 6 mushrooms
  • 6 cloves garlic
  • 6 oz. organic chicken breast fillet
  • 1 yellow squash, alternated with 1 zucchini
  • 1 cup sauvignon blanc
  • 32 oz. “unsalted” chicken broth, which still contains 24% of the sodium RDA

Pour wine into a 6-quart Instant Pot; cut and strain squeezed lemon; cut chicken into 1/4″ cubes and add; start mixture on Sauté. Wash and cut celery and stir in. Wash and cut carrots and stir in.

When pot boils around 8 minutes, add chicken broth and stir. Wash mushrooms, slicing into spoon sizes.

Wash and slice yellow squash / zucchini. Crush and peel garlic, tear but don’t slice. Turn off pot when it boils again around 15 minutes.

Wait 2-3 minutes for boiling to subside, then add yellow squash / zucchini, mushrooms, garlic, whole tomatoes. Let set for 20 minutes; stir bottom-to-top 5 and 15 minutes after turning off, and again before serving.

AGE-less Chicken Vegetable Soup is tasty enough to not need seasoning.

Eat oats today!

This 2020 food chemistry review provided phenolic-compound reasons to eat oats:

“Phenolamides result from the conjugation of hydroxycinnamic acids with amines. These products contain a variety of metabolic, chemical, and functional capabilities due to the large number of possible combinations among the parent compounds.

Of the currently known phenolamides, the most common are avenanthramides (AVAs), which are unique in oats. AVAs possess anti-inflammatory, anti-itch, anti-atherosclerosis, antioxidant, anti-cancer, anti-obesity, anti-fungal, anti-microbial, and neuroprotective properties.

Twenty-nine C-type AVAs have been identified in oats, and twenty-six A-type AVAs.

  • C-type AVAs in commercially available oat products range from 36.49-61.77 mg/kg (fresh weight).
  • A-type AVAs represent approximately 22.5% of total AVA levels in regular oats and 24.7-33.0% in commercial sprouted oats.

Steeping raw groats increased AVA concentrations.”

These reviews were referenced:

“Since publication of these two reviews, a few new studies reported AVAs’ beneficial health effects, mainly related to their anti-inflammatory and anti-cancer activities. AVAs can:

  • Significantly decrease IL-6, IL-8, and MCP-1 in endothelial cells;
  • Inhibit IL-1β- and TNF-α-induced NF-κB activation; as well as
  • Expression of adhesion molecules; and
  • Adhesion of monocytes to endothelial cell monolayer.

In 2020, the first evaluation of anti-inflammation effects of A-type AVAs was published from our own group. Fifteen A-type AVAs from commercial sprouted oat products interacted with lipopolysaccharide-induced nitric oxide production and iNOS expression.

Colloidal oatmeal’s natural components, AVAs, help to restore and maintain skin barrier function. AVAs are safe, well tolerated, and can be effective as adjuvant treatment in atopic dermatitis.

In one mouse model, a C-type AVA was able to mitigate many adverse effects of Alzheimer’s Disease. It restored hippocampal long-term potentiation and synaptic function, enhanced memory function, suppressed pro-inflammatory cytokines TNF-α and IL-6 levels, reduced caspase-3 levels, and increased pS9GSK-3β and IL-10 levels.

AVAs downregulated expression of hTERT and MDR1, pro-survival genes for cancer cells, and COX-2 mRNA and PGE2 levels, known pro-inflammatory markers. AVAs induced apoptosis by activating caspases 8, 3, and 2.”

https://pubs.acs.org/doi/10.1021/acs.jafc.0c02605 “The Chemistry and Health Benefits of Dietary Phenolamides” (not freely available)


Hadn’t thought about sprouting oats before this paper.

Clearing out the 2020 queue of interesting papers

I’ve partially read these 39 studies and reviews, but haven’t taken time to curate them.

Early Life

  1. Intergenerational Transmission of Cortical Sulcal Patterns from Mothers to their Children (not freely available)
  2. Differences in DNA Methylation Reprogramming Underlie the Sexual Dimorphism of Behavioral Disorder Caused by Prenatal Stress in Rats
  3. Maternal Diabetes Induces Immune Dysfunction in Autistic Offspring Through Oxidative Stress in Hematopoietic Stem Cells
  4. Maternal prenatal depression and epigenetic age deceleration: testing potentially confounding effects of prenatal stress and SSRI use
  5. Maternal trauma and fear history predict BDNF methylation and gene expression in newborns
  6. Adverse childhood experiences, posttraumatic stress, and FKBP5 methylation patterns in postpartum women and their newborn infants (not freely available)
  7. Maternal choline supplementation during the third trimester of pregnancy improves infant information processing speed: a randomized, double‐blind, controlled feeding study
  8. Preterm birth is associated with epigenetic programming of transgenerational hypertension in mice
  9. Epigenetic mechanisms activated by childhood adversity (not freely available)

Epigenetic clocks

  1. GrimAge outperforms other epigenetic clocks in the prediction of age-related clinical phenotypes and all-cause mortality (not freely available)
  2. Epigenetic age is a cell‐intrinsic property in transplanted human hematopoietic cells
  3. An epigenetic clock for human skeletal muscle
  4. Immune epigenetic age in pregnancy and 1 year after birth: Associations with weight change (not freely available)
  5. Vasomotor Symptoms and Accelerated Epigenetic Aging in the Women’s Health Initiative (WHI) (not freely available)
  6. Estimating breast tissue-specific DNA methylation age using next-generation sequencing data

Epigenetics

  1. The Intersection of Epigenetics and Metabolism in Trained Immunity (not freely available)
  2. Leptin regulates exon-specific transcription of the Bdnf gene via epigenetic modifications mediated by an AKT/p300 HAT cascade
  3. Transcriptional Regulation of Inflammasomes
  4. Adipose-derived mesenchymal stem cells protect against CMS-induced depression-like behaviors in mice via regulating the Nrf2/HO-1 and TLR4/NF-κB signaling pathways
  5. Serotonin Modulates AhR Activation by Interfering with CYP1A1-Mediated Clearance of AhR Ligands
  6. Repeated stress exposure in mid-adolescence attenuates behavioral, noradrenergic, and epigenetic effects of trauma-like stress in early adult male rats
  7. Double-edged sword: The evolutionary consequences of the epigenetic silencing of transposable elements
  8. Blueprint of human thymopoiesis reveals molecular mechanisms of stage-specific TCR enhancer activation
  9. Statin Treatment-Induced Development of Type 2 Diabetes: From Clinical Evidence to Mechanistic Insights
  10. Rewiring of glucose metabolism defines trained immunity induced by oxidized low-density lipoprotein
  11. Chronic Mild Stress Modified Epigenetic Mechanisms Leading to Accelerated Senescence and Impaired Cognitive Performance in Mice
  12. FKBP5-associated miRNA signature as a putative biomarker for PTSD in recently traumatized individuals
  13. Metabolic and epigenetic regulation of T-cell exhaustion (not freely available)

Aging

  1. Molecular and cellular mechanisms of aging in hematopoietic stem cells and their niches
  2. Epigenetic regulation of bone remodeling by natural compounds
  3. Microglial Corpse Clearance: Lessons From Macrophages
  4. Plasma proteomic biomarker signature of age predicts health and life span
  5. Ancestral stress programs sex-specific biological aging trajectories and non-communicable disease risk

Broccoli sprouts

  1. Dietary Indole-3-Carbinol Alleviated Spleen Enlargement, Enhanced IgG Response in C3H/HeN Mice Infected with Citrobacter rodentium
  2. Effects of caffeic acid on epigenetics in the brain of rats with chronic unpredictable mild stress
  3. Effects of sulforaphane in the central nervous system
  4. Thiol antioxidant thioredoxin reductase: A prospective biochemical crossroads between anticancer and antiparasitic treatments of the modern era (not freely available)
  5. Quantification of dicarbonyl compounds in commonly consumed foods and drinks; presentation of a food composition database for dicarbonyls (not freely available)
  6. Sulforaphane Reverses the Amyloid-β Oligomers Induced Depressive-Like Behavior (not freely available)

Eat broccoli sprouts for your eyes

This 2020 review subject concerned a leading cause of blindness:

“Advanced glycation end products (AGEs) are toxic compounds that have adverse effects on many tissues including the retina and lens. AGEs promote formation of reactive oxygen species (ROS), which, in turn, boost production of AGEs, a vicious cycle.

Diabetic retinopathy (DR) is a devastating microvascular complication of diabetes mellitus and the leading cause of blindness in working-age adults. The onset and development of DR is multifactorial. Lowering AGEs accumulation may represent a potential therapeutic approach.

Once AGEs are formed, most are irreversible. Cataracts are perhaps the earliest pathobiology of AGEs:

Nε-(carboxymethyl)-lysine (CML) [a representative AGE] in lens crystallins from diabetic (■) and non-diabetic (♦) subjects as a function of age.

The glyoxalase system is a protective mechanism that slows down synthesis of AGEs by limiting reactive dicarbonyls formed during sugar metabolism. Glutathione (GSH) in the eye is present at concentrations many times blood levels, and is a critical component of the glyoxalase system.

Proteomic analysis identified GLO1 [glyoxalase 1] as a protein differentially expressed in cells treated with sulforaphane. Sulforaphane inhibited AGEs-derived pericyte damage and delayed diabetes-induced retinal photoreceptor cell degeneration.

No AGE inhibitors have reached clinical use. The glyoxalase system and discovery of compounds that enhance this detoxifying activity represent a therapeutic alternative to fight glycation-derived damage.”

https://www.mdpi.com/2076-3921/9/11/1062/htm “Glyoxalase System as a Therapeutic Target against Diabetic Retinopathy”


The above graph – plotting a cataract AGE level against chronological age – represented life stage progression without effective personal agency, without taking responsibility for your one precious life.

Citation 156 was Activation of Nrf2 attenuates carbonyl stress induced by methylglyoxal in human neuroblastoma cells: Increase in GSH levels is a critical event for the detoxification mechanism (not freely available):

“The present study focused on the methylglyoxal (MG) detoxification mechanism. MG treatment resulted in accumulation of modified proteins bearing the structure of AGEs.

This accumulation was suppressed by activation of the Nrf2 pathway prior to MG exposure via pre-treatment with an Nrf2 activator:

Although pre-treatment with the Nrf2 activator did not affect mRNA levels of GLO1, expressions of GCL and xCT mRNA, involved in GSH synthesis, were induced prior to increase in GSH levels.

These results indicated that increase in GSH levels promoted formation of the GLO1 substrate, thereby accelerating MG metabolism via the glyoxalase system and suppressing its toxicity. Promotion of GSH synthesis via the Nrf2/Keap1 pathway is important in MG detoxification.”

Continued in Part 2.


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Nrf2 and Parkinson’s disease

This 2020 rodent study investigated a long non-coding RNA (lncRNA) in Parkinson’s disease:

“Knockdown of MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) lncRNA inhibited elevated nuclear factor (erythroid-derived 2)-like-2 factor (NRF2) expression, thereby inhibiting inflammasome activation and ROS (reactive oxygen species) production. MALAT1 was shown to promote neuroinflammation by recruiting enhancer of zeste homologue 2 (EZH2) to the promoter of NRF2, suppressing Nrf2 expression.

EZH2 catalyses generation of trimethylated H3K27 (H3K27me3) from histone H3 at lysine 27 (H3K27). EZH2 plays an important role in regulating the essential genes for inflammation in microglial activation, which induces neurodegeneration in the central nervous system.

Our results also validated MALAT1 binding to EZH2 in LPS-treated BV2 cells, which further recruited H3K27me3 to the gene promoter loci of Nrf2 to repress Nrf2 transcription. Although silencing MALAT1 did not alter global EZH2 expression levels, decreased binding between EZH2 and the Nrf2 promoter was observed. Previous studies have revealed that lncRNAs regulate the function of EZH2 in a similar manner.

MALAT1 epigenetically inhibits NRF2, thereby inducing inflammasome activation and ROS production in PD mouse and microglial cell models. To the best of our knowledge, it is first report of the important role of EZH2 in regulating the expression of Nrf2 to activate microglial inflammation.”

https://molecularbrain.biomedcentral.com/articles/10.1186/s13041-020-00656-8 “LncRNA MALAT1 facilitates inflammasome activation via epigenetic suppression of Nrf2 in Parkinson’s disease”


Eat broccoli sprouts today! referenced a letter to the editor that cited The Ezh2 Polycomb Group Protein Drives an Aggressive Phenotype in Melanoma Cancer Stem Cells and is a Target of Diet Derived Sulforaphane which found:

“SFN treatment is associated with reduced Ezh2 level and H3K27me3 formation.”

However, that study didn’t link sulforaphane’s main effect of Nrf2 signaling pathway activation to these specific treatment effects.


This post was inspired by our latest subscriber, Dr. Albert F. Wright, who is battling PD with – among other treatments – broccoli seeds.

Dietary contexts matter

Two papers illustrated how actions of food compounds are affected by their contexts. The first was a 2020 UCLA rodent study:

“Long-chain polyunsaturated fatty acids (PUFAs), particularly omega-3 (n-3) PUFAs, have been indicated to play important roles in various aspects of human health. Controversies are observed in epidemiological and experimental studies regarding the benefits or lack of benefits of n-3 PUFAs.

Dietary docosahexaenoic acid (DHA; 22:6 n-3) supplementation improved select metabolic traits and brain function, and induced transcriptomic and epigenetic alterations in hypothalamic and hippocampal tissues in both context-independent and context-specific manners:

  • In terms of serum triglyceride, glycemic phenotypes, insulin resistance index, and memory retention, DHA did not affect these phenotypes significantly when examined on the chow diet background, but significantly improved these phenotypes in fructose-treated animals.
  • Genes and pathways related with tissue structure were affected by DHA regardless of the dietary context, although the direction of changes are not necessarily the same between contexts. These pathways may represent the core functions of DHA in maintaining cell membrane function and cell signaling.
  • DHA affected the mTOR signaling pathway in hippocampus. In the hypothalamus, altered pathways were more related to innate immunity, such as cytokine-cytokine receptors, NF-κB signaling pathway, and Toll-like receptor signaling pathway.

DHA exhibits differential influence on epigenetic loci, genes, pathways, and metabolic and cognitive phenotypes under different dietary contexts.”

https://onlinelibrary.wiley.com/doi/10.1002/mnfr.202000788 “Multi‐tissue Multi‐omics Nutrigenomics Indicates Context‐specific Effects of DHA on Rat Brain” (not freely available)


A human equivalent age period of the subjects was 12 to 20 years old. If these researchers want to make their study outstanding, they’ll contact their UCLA colleague Dr. Steven Horvath, and apply his new human-rat relative biological age epigenetic clock per A rejuvenation therapy and sulforaphane.

The second paper was a 2016 review Interactions between phytochemicals from fruits and vegetables: Effects on bioactivities and bioavailability (not freely available):

“The biological activities of food phytochemicals depend upon their bioaccessibility and bioavailability which can be affected by the presence of other food components including other bioactive constituents. For instance, α-tocopherol mixed with a flavonol (kaempferol or myricetin) is more effective in inhibiting lipid oxidation induced by free radicals than each component alone.

Interactions of phytochemicals may enhance or reduce the bioavailability of a given compound, depending on the facilitation/competition for cellular uptake and transportation. For example, β-carotene increases the bioavailability of lycopene in human plasma, and quercetin-3-glucoside reduces the absorption of anthocyanins.

Combinations of food extracts containing hydrophilic antioxidants and lipophilic antioxidants showed very high synergistic effects on free radical scavenging activities. A number of phytochemical mixtures and food combinations provide synergistic effects on inhibiting inflammation.

More research should be conducted to understand mechanisms of bioavailability interference considering physiological concentrations, food matrices, and food processing.”


Each of us can set appropriate contexts for our food consumption. Broccoli sprout synergies covered how I take supplements and broccoli sprouts together an hour or two before meals to keep meal contents from lowering sulforaphane bioavailability.

Combinations of my 19 supplements and broccoli sprouts are too many (616,645) for complete analyses. Just pairwise comparisons like the second paper’s example below would be 190 combinations.

binary isobologram

Contexts for each combination’s synergistic, antagonistic, or additive activities may also be influenced by other combinations’ results.

My consumption of flax oil (alpha linolenic acid C18:3) probably has effects similar to DHA since it’s an omega-3 PUFA and I take it with food. The first study’s human equivalent DHA dose was 100mg/kg, with its citation for clinical trials stating “1–9 g/day (0.45–4% of calories) n-3 PUFA.”

A 2020 review Functional Ingredients From Brassicaceae Species: Overview and Perspectives had perspectives such as:

“In many circumstances, the isolated bioactive is not as bioavailable or metabolically active as in the natural food matrix.”

It discussed categories but not combinations of phenolics, carotenoids, phytoalexins, terpenes, phytosteroids, and tocopherols, along with more well-known broccoli compounds.


Diving for breakfast

Treating psychopathological symptoms will somehow resolve causes?

This 2020 Swiss review subject was potential glutathione therapies for stress:

“We examine available data supporting a role for GSH levels and antioxidant function in the brain in relation to anxiety and stress-related psychopathologies. Several promising compounds could raise GSH levels in the brain by either increasing availability of its precursors or expression of GSH-regulating enzymes through activation of Nrf2.

GSH is the main cellular antioxidant found in all mammalian tissues. In the brain, GSH homeostasis has an additional level of complexity in that expression of GSH and GSH-related enzymes are not evenly distributed across all cell types, requiring coordination between neurons and astrocytes to neutralize oxidative insults.

Increased energy demand in situations of chronic stress leads to mitochondrial ROS overproduction, oxidative damage and exhaustion of GSH pools in the brain.

Several compounds can function as precursors of GSH by acting as cysteine (Cys) donors such as taurine or glutamate (Glu) donors such as glutamine (Gln). Other compounds stimulate synthesis and recycling of GSH through activation of the Nrf2 pathway including sulforaphane and melatonin. Compounds such as acetyl-L-carnitine can increase GSH levels.”

https://www.sciencedirect.com/science/article/abs/pii/S0149763419311133 “Therapeutic potential of glutathione-enhancers in stress-related psychopathologies” (not freely available)


Many animal studies of “stress-related psychopathologies” were cited without noting applicability to humans. These reviewers instead had curious none-of-this-means-anything disclaimers like:

“Comparisons between studies investigating brain disorders of such different nature such as psychiatric disorders or neurodegenerative diseases, or even between brain or non-brain related disorders should be made with caution.”

Regardless, this paper had informative sections for my 27th week of eating broccoli sprouts every day.

1. I forgot to mention in Broccoli sprout synergies that I’ve taken 500 mg of trimethyl glycine (aka betaine) twice a day for over 15 years. Section 3.1.2 highlighted amino acid glycine:

“Endogenous synthesis is insufficient to meet metabolic demands for most mammals (including humans) and additional glycine must be obtained from diet. While most research has focused on increasing cysteine levels in the brain in order to drive GSH synthesis, glycine supplementation alone or in combination with cysteine-enhancing compounds are gaining attention for their ability to enhance GSH.”

2. Amino acid taurine dropped off my supplement regimen last year after taking 500 mg twice a day for years. It’s back on now after reading Section 3.1.3:

“Most studies that reported enhanced GSH in the brain following taurine treatment were performed under a chronic regimen and used in age-related disease models.

Such positive effects of taurine on GSH levels may be explained by the fact that cysteine is the essential precursor to both metabolites, whereby taurine supplementation may drive metabolism of cysteine towards GSH synthesis.”

3. A study in Upgrade your brain’s switchboard with broccoli sprouts was cited for its potential:

“Thalamic GSH values significantly correlated with blood GSH levels, suggesting that peripheral GSH levels may be a marker of brain GSH content. Studies point to the capacity of sulforaphane to function both as a prophylactic against stress-induced behavioral changes and as a positive modulator in healthy animals.”


Sunrise minus 5 minutes

Unraveling oxytocin – is it nature’s medicine?

This 2020 review attempted to consolidate thousands of research papers on oxytocin:

“Chemical properties of oxytocin make this molecule difficult to work with and to measure. Effects of oxytocin are context-dependent, sexually dimorphic, and altered by experience. Its relationship to a related hormone, vasopressin, have created challenges for its use as a therapeutic drug.

Widely used medical interventions i.e.:

  • Exogenous oxytocin, such as Pitocin given to facilitate labor;
  • Opioid medications that block the oxytocin system; or
  • Cesarean sections that alter exposure to endogenous oxytocin

have lasting consequences for the offspring and/or mother.

Such exposures hold the potential to have epigenetic effects on the oxytocin systems, including changes in DNA methylation. These changes in turn would have lasting effects on the expression of receptors for oxytocin, leaving individuals differentially able to respond to oxytocin and also possibly to the effects of vasopressin.

Regions with especially high levels of OXTR [oxytocin receptor gene] are:

  • Various parts of the amygdala;
  • Bed nucleus of the stria terminalis;
  • Nucleus accumbens;
  • Brainstem source nuclei for the autonomic nervous system;
  • Systems that regulate the HPA axis; as well as
  • Brainstem tissues involved in pain and social attention.

Oxytocin protects neural cells against hypoxic-ischemic conditions by:

  • Preserving mitochondrial function;
  • Reducing oxidative stress; and
  • Decreasing a chromatin protein that is released during inflammation

which can activate microglia through the receptor for advanced glycation end products (RAGE). RAGE acts as an oxytocin-binding protein facilitating the transport of oxytocin across the blood-brain barrier and through other tissues.

Directionality of this transport is 5–10 times higher from the blood to the brain, in comparison with brain to blood transport. Individual differences in RAGE could help to predict cellular access to oxytocin and might also facilitate access to oxytocin under conditions of stress or illness.

Oxytocin and vasopressin and their receptors are genetically variable, epigenetically regulated, and sensitive to stressors and diet across the lifespan. As one example, salt releases vasopressin and also oxytocin.

Nicotine is a potent regulator of vasopressin. Smoking, including prenatal exposure of a fetus, holds the potential to adjust this system with effects that likely differ between males and females and that may be transgenerational.

Relative concentrations of endogenous oxytocin and vasopressin in plasma were associated with:

These studies support the usefulness of measurements of both oxytocin and vasopressin but leave many empirical questions unresolved.

The vast majority of oxytocin in biosamples evades detection using conventional approaches to measurement.”

https://pharmrev.aspetjournals.org/content/pharmrev/72/4/829.full.pdf “Is Oxytocin Nature’s Medicine?”


I appreciated efforts to extract worthwhile oxytocin research from countless poorly performed studies, research that wasted resources, and research that actually detracted from science.

I was disappointed that at least one of the reviewers didn’t take this review as an opportunity to confess their previous wastes like three flimsy studies discussed in Using oxytocin receptor gene methylation to pursue an agenda.

Frank interpretations of one’s own study findings to acknowledge limitations is one way researchers can address items upfront that will be questioned anyway. Such analyses also indicate a goal to advance science.

Although these reviewers didn’t provide concrete answers to many questions, they highlighted promising research areas, such as:

  • Improved approaches to oxytocin measurements;
  • Prenatal epigenetic experience associations with oxytocin and OXTR; and
  • Possible transgenerational transmission of these prenatal epigenetic experiences.