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:

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

See Switch on your Nrf2 signaling pathway for an interview with the author.

How will you feel?

Consider this a partial repost of Moral Fiber:

“We are all self-reproducing bioreactors. We provide an environment for trillions of microbes, most of which cannot survive for long without the food, shelter and a place to breed that we provide.

They inhabit us so thoroughly that not a single tissue in our body is sterile. Our microbiome affects our development, character, mood and health, and we affect it via our diet, medications and mood states.

The microbiome:

  • Affects our thinking and our mood;
  • Influences how we develop;
  • Molds our personalities;
  • Our sociability;
  • Our responses to fear and pain;
  • Our proneness to brain disease; and
  • May be as or more important in these respects than our genetic makeup.

Dysbiosis has become prevalent due to removal of prebiotic fibers from today’s ultra-processed foods. I believe that dietary shift has created a generation of humans less able to sustain or receive love.

They suffer from reduced motivation and lower impulse control. They are more anxious, more depressed, more selfish, more polarized, and therefore more susceptible to the corrosive politics of identity.


Other recent blog posts by Dr. Paul Clayton and team include Skin in The Game and Kenosha Kids.

Image from Thomas Cole : The Consummation, The Course of the Empire (1836) Canvas Gallery Wrapped Giclee Wall Art Print (D4060)

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 a range of germination parameters (hulled / dehulled seeds of two varieties, for 1-to-9 days, at 12-to-20°C). And 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 a follow-up study 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 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 lemon
  • 3 Roma tomatoes
  • 4 large carrots
  • 6 stalks organic celery
  • 6 mushrooms
  • 6 cloves garlic
  • 6 oz. organic chicken breast fillet
  • 1 cup organic pasta
  • 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; wash and scrub carrots; stir pot at 4 minutes; stir in celery at 5 minutes.

Cut and stir in carrots. Wash mushrooms, slicing only if supersized. When pot boils around 10 minutes, add chicken broth and stir.

Wash and slice yellow squash / zucchini; crush and peel garlic but don’t slice. When pot boils again around 15 minutes, stir in pasta; turn off pot.

Add yellow squash / zucchini, mushrooms, garlic; wash and add 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, at least when freshly prepared.

Oat sprouts analysis

A research group published two 2020 studies on sprouting oat seeds. Their first study produced evidence over a range of germination parameters (hulled / dehulled seeds of two varieties, for 1-to-9 days, at 12-to-20°C):

“The aim was to investigate the influence of germination period and temperature on protein profile, bioactive potential (β-glucan and phenolic contents), antioxidant capacity, and on activity of enzymes (α-amylase, protease and lipase) from hulled and dehulled oat varieties. Multi-response optimization was used to identify optimal germination conditions that maximize sprouted oat flour quality.

  • Hulled (variety Barra) and dehulled (variety Meeri) germination was performed in dark at different temperatures (12, 14, 16, 18, and 20 ◦C) and duration (24, 60, 96, 156, and 216 h).
  • Germination at 16 ◦C for 216 h and 20 ◦C for 96 h produced the highest protein accumulation in varieties Barra and Meeri, respectively.
  • Germination for short periods (24–96 h) combined with medium temperatures (12–16 ◦C) retained β-glucan levels, but longer germination times (156–216 h) caused reductions of 47–64%. Endogenous β-glucanases increase activity during germination, causing hydrolysis of β-glucan.
  • Free phenolic compound content was between 1.6-fold and 2.8-fold higher when germination took place at high temperatures (16–18 ◦C) for longer times.
  • Antioxidant capacity was between 1.4 and 4.5-fold higher. High temperatures (16–18 ◦C) and longer germination times (156–216 h) positively influenced antioxidant capacity.

The effect of germination conditions strongly depended on genetic diversity and presence/absence of hull.

Optimal germination conditions maximize contents of β-glucan, free phenolic compounds, protease activity, and antioxidant capacity, and minimize activity of undesirable enzymes α-amylase and lipase. For variety Meeri, that corresponded to 18 ◦C and time 120 h.”

https://www.sciencedirect.com/science/article/abs/pii/S0023643820309440 “Changes in protein profile, bioactive potential and enzymatic activities of gluten-free flours obtained from hulled and dehulled oat varieties as affected by germination conditions” (not freely available)


Their second 2020 study analyzed properties of 4-day-old oat sprouts. Dehulled oat seeds (variety Meeri) were soaked at room temperature for 4 hours, then germinated in darkness at 18°C with humidity ≥ 90%.

“Sprouted oat powder was an excellent source of protein (10.7%), β-glucan (2.1%), thiamine, riboflavin, and minerals (P, K, Mg and Ca). It presented better amino acid and fatty acid compositions, and levels of γ-aminobutyric acid [GABA], free phenolics, and antioxidant capacity than control.

Protein content (g/100 g) and amino acid profile (g/100 g protein). Different letters within a row indicate p ≤ 0.05 statistical differences.

During germination, proteins are partially hydrolyzed increasing availability of free amino acids. Activity of glutamate decarboxylase enzyme is enhanced.

However, no significant reduction of glutamate content was observed. Glutamate is used for GABA and protein synthesis, but it is also produced by protein hydrolysis, glutamine synthetase-glutamate synthase cycle, and GABA transaminase reactions.

Sprouted oat powder exhibited 2.5-fold higher SPC [soluble (free) phenolic compounds] levels. De novo synthesis of phenolic compounds or liberation of phenolic compounds that are linked to macromolecules due to cell wall dismantling during germination could explain enhancement of SPC.

Sprouted oat powder displayed a 3-fold higher antioxidant capacity. Release of bound phenolic compounds and de novo synthesis of avenanthramides might be responsible.

Hydrolysis of β-glucan might also cause an increase in oxygen radical absorbance capacity. β-glucan oligosaccharides exhibit high radical scavenging activity and reducing power, and that could be related with exposure of their active hydroxyl groups and decrease of intermolecular hydrogen bonding during germination.”

https://www.sciencedirect.com/science/article/abs/pii/S0308814620318343 “Sprouted oat as a potential gluten-free ingredient with enhanced nutritional and bioactive properties” (not freely available)


Both studies started germination by:

“Twenty grams of oat seeds were used for germination. Soaking (1:6 ratio, w/v) was performed at room temperature (20 ◦C ±2 ◦C) for 4 h.”

Neither study included estimates of germination rates. I contacted the corresponding coauthor for that information, and they replied:

“The germination rate in hulled oat varieties was around 95% and in
dehulled one around 55-70% depending on the germination conditions.”


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 the formation of reactive oxygen species (ROS), which, in turn, boost the 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.


PXL_20201121_113656177

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

Eat broccoli sprouts to pivot your internal environment’s signals

Two 2020 reviews covered some aspects of a broccoli sprouts primary action – NRF2 signaling pathway activation:

“Full understanding of the properties of drug candidates rely partly on the identification, validation, and use of biomarkers to optimize clinical applications. This review focuses on results from clinical trials with four agents known to target NRF2 signaling in preclinical studies, and evaluates the successes and limitations of biomarkers focused on:

  • Expression of NRF2 target genes [AKR1, GCL, GST, HMOX1, NQO1] and others [HDAC, HSP];
  • Inflammation [COX-2, CRP, IL-1β, IL-6, IP-10, MCP-1, MIG, NF-κB, TNF-α] and oxidative stress [8-OHdG, Cys/CySS, GSH/GSSG] biomarkers;
  • Carcinogen metabolism and adduct biomarkers in unavoidably exposed populations; and
  • Targeted and untargeted metabolomics [HDL, LDL, TG].

No biomarkers excel at defining pharmacodynamic actions in this setting.

SFN [sulforaphane] seems to affect multiple downstream pathways associated with anti-inflammatory actions. NRF2 signaling may be but one pivotal pathway.

SFN is generally considered to be the most potent natural product inducer of Nrf2 signaling. Studies in which these actions are diminished or abrogated in parallel experiments in Nrf2-disrupted mice provide the strongest lines of evidence for a key role of this transcription factor in its actions.

It is equally evident that other modes of action contribute to the molecular responses to SFN in animals and humans. Such polypharmacy may well contribute to the efficacy of the agent in disease prevention and mitigation, but obfuscates the value of specific pharmacodynamic biomarkers in the clinical development and evaluation of SFN.”

https://www.mdpi.com/2076-3921/9/8/716/htm “Current Landscape of NRF2 Biomarkers in Clinical Trials”


Why do researchers still not use epigenetic clocks in sulforaphane clinical trials? Forty mentions of disease in this review, but no consideration of aging?

This was another example of how researchers – even when stuck in a paradigm they know doesn’t sufficiently explain their area (“No biomarkers excel”) – don’t investigate other associated research areas. Why not?

Here’s what Part 2 of Rejuvenation therapy and sulforaphane had to say to those stuck on biomarkers:

“While clinical biomarkers have obvious advantages (being indicative of organ dysfunction or disease), they are neither sufficiently mechanistic nor proximal to fundamental mechanisms of aging to serve as indicators of them. It has long been recognized that epigenetic changes are one of several primary hallmarks of aging.

DNA methylation epigenetic clocks capture aspects of biological age.”


The second review Epigenetic Regulation of NRF2/KEAP1 by Phytochemicals also completely whiffed on epigenetic clocks. One mention of aging in this review, but it wasn’t of:

  • Citation 104 from Archives of Gerontology and Geriatrics; nor of
  • Citation 108 from the March 31, 2020, Aging journal; nor of
  • Citation 131 “Dietary epigenetics in cancer and aging.”

But epigenetic clock and aging associations were certainly in this review’s scope. For example, Citation 119 said:

“Nrf2 transcriptional activity declines with age, leading to age-related GSH loss among other losses associated with Nrf2-activated genes. This effect has implications, too, for decline in vascular function with age. Some of the age-related decline in function can be restored with Nrf2 activation by SFN.”

Why would people bother with phytochemicals (buzzword “compounds produced by plants”) unless to either ameliorate symptoms or address causes?

“Epigenetic Regulation of NRF2/KEAP1 by Phytochemicals” doesn’t occur in just laboratory situations. It’s also part of daily life.

These reviewers were straight-forward with side effects for two of the first review’s four items:

“The best known NRF2 activator that has obtained clinical approval is dimethyl fumarate for the treatment of multiple sclerosis. However, it has several side effects, including allergic reactions and gastrointestinal disturbance. There are a few related agents in clinical trials, such as Bardoxolone and SFX-01, a synthetic derivative of sulforaphane, which also exhibit less than desirable outcomes.”


Natural sources of melatonin

This 2020 review subject was melatonin:

“The emergence of naturally occurring melatonin and its isomers in fermented foods has opened an exciting new research area. Melatonin is a hormone, an indolamine that predominantly appears in plants, microorganisms, and mammals.

The precursor of this molecule is solely the amino acid L‐tryptophan. Melatonin ensures a circadian and seasonal signal to vertebrate organisms; it is synthesized through a cascade of enzymatic reactions producing melatonin from serotonin in its final phases. The synthesis of melatonin is observed in almost all organs.

One melatonin molecule has the capacity to scavenge up to 10 ROS versus the other antioxidants that scavenge 1 or even less ROS. Melatonin antioxidant properties are accomplished with the indole ring that stimulates enzyme production (i.e., superoxide dismutase (SOD), glutathione‐peroxidase (Gpx), and catalase (CAT)), which mitigate free radicals to less toxic substances.

In addition to antioxidant properties, it plays a fundamental role in the modulation of various physiological functions, including circadian rhythmicity, bone integrity, and functionalization of the human reproductive system.

The presence of melatonin and its isomers is not exclusive for grapes and grape‐derived products. Other fruits such as sweet and sour cherries and fermented juices of orange and pomegranate may be also of interest.”

https://onlinelibrary.wiley.com/doi/full/10.1111/1541-4337.12639 “Naturally occurring melatonin: Sources and possible ways of its biosynthesis”


Treating psychopathological symptoms will somehow resolve causes?

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

“We examine the 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 the availability of its precursors or the 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 the expression of GSH and GSH-related enzymes are not evenly distributed across all cell types, requiring the 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 the synthesis and recycling of GSH through the 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. The 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 the amino acid glycine:

“Endogenous synthesis is insufficient to meet metabolic demands for most mammals (including humans) and additional glycine must be obtained from the 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. The 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 the 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.

Get serious about advanced glycation end products (AGEs)

Ever heard about AGEs? Here are three papers that describe how AGEs affect humans.

First is a 2020 Italian review Common Protective Strategies in Neurodegenerative Disease: Focusing on Risk Factors to Target the Cellular Redox System:

“Neurodegenerative disease is an umbrella term for different conditions which primarily affect the neurons in the human brain. Currently, neurodegenerative diseases are incurable, and the treatments available only control the symptoms or delay the progression of the disease.

Neurotoxicity can be induced by glycation reactions. Since glycation is a nonenzymatic process, proteins characterized by a slow turnover are those that more easily accumulate AGEs.

Methylglyoxal (MG) can occur as glycolysis by-product, but it is also present in foods (especially cooked and baked), beverages (mainly those fermented), and cigarette smoke, and it is considered the most potent precursor of AGE formation. More than 20 different AGEs have been identified in foods and in human tissues.

AGE accumulation, oxidative stress, and inflammation are related to AGE ability to bind specific receptors called RAGE. RAGE expression increases during aging, cancer, cardiovascular diseases, AD [Alzheimer’s], PD [Parkinson’s], and other neurodegenerative diseases.”


A 2015 study by some of the same authors Antiglycative activity of sulforaphane: a new avenue to counteract neurodegeneration? was cited for a treatment in addition to changing one’s diet to be AGE-less.

“When MG production is increased by high glucose or oxidative stress, glycated proteins accumulate in the brain and lead to glycative stress, playing a fundamental role in the establishment of different neurodegenerative disorders.

Our results indicated that SF [sulforaphane] counteracts ROS by two possible mechanisms of action: an increase of intracellular GSH [glutathione] levels and an enhancement of MG-detoxification through the up-regulation of the glyoxalase (GLO1) systems. GLO1 up-regulation is mediated by the transcription factor Nrf2. SF has been demonstrated to activate Nrf2.

Another mechanism by which SF exerts its neuroprotective activity against MG-induced glycative damage is the modulation of mitogen-activated protein kinase (MAPK) signaling pathways involved in apoptotic cell death. All MAPK signaling pathways are activated in AD.

Brain-derived neurotrophic factor (BDNF) is associated with neuronal survival through its interactions with the tyrosine receptor kinase B (TrkB) and p75 cellular receptors. BDNF expression levels are reduced in the brain of AD patients. SF pre-treatment, before MG addition, not only further increased BDNF levels, but also significantly induced TrkB protein levels reverting MG negative effect on this receptor.

SF totally reverts the reduction of glucose uptake caused by MG exposure. SF can be defined as a multitarget agent modulating different cellular functions leading to a pro-survival frame of particular importance in the prevention / counteraction of multifactorial neurodegenerative diseases.”


A 2020 review Non-enzymatic covalent modifications: a new link between metabolism and epigenetics investigated glycation:

“Non-enzymatic covalent modifications (NECMs) by chemically reactive metabolites have been reported to manipulate chromatin architecture and gene transcription. Unlike canonical post-translational modifications (PTMs), NECMs accumulate over time and are much more dependent on the cellular microenvironment.

A. Guanine residues in DNA and RNA can undergo methylglyoxal glycation, thereby inducing DNA and RNA damage. This DNA damage has few corresponding repair pathways.

B. Histones are primary glycation substrates because of their long half-lives and abundant lysine and arginine residues. Histone glycation was found to induce epigenetic dysregulation through three distinct mechanisms:

  1. Competition with essential enzymatic PTMs for sites (e.g., glycation adducts replace H3K4me3 and H3R8me2);
  2. Changing the charge states of histone tails and subsequently affecting the compaction state of the fiber; and
  3. Altering three-dimensional chromatin architecture by inducing both histone-histone and histone-DNA crosslinking.

Epigenetic impacts of histone glycation were shown to be dependent on sugar concentration and exposure time. Histone and DNA glycation may lead to long term epigenetic impacts on immune responses.

C. Glycation of multiple lysine residues of NRF2 inhibits its oncogenic function. Sugar molecules can influence epigenetic events through glycation of transcription factors and/or their associated regulatory proteins.”

The Transcription factor glycation section referenced a 2011 paper Regulation of the Keap1/Nrf2 system by chemopreventive sulforaphane: implications of posttranslational modifications:

“Nrf2 mRNA level is unaffected by treatment with sulforaphane, suggesting that cellular expression of Nrf2 protein is posttranscriptionally regulated. Posttranslational modifications of Keap1 and Nrf2 proteins seem to play an important role in the regulation of ARE‐dependent gene expression.”


“Neurodegenerative diseases are incurable?” Take responsibility for your own one precious life.

Other curated AGEs papers include: