Giving children allergies with pets

This 2021 human study investigated development and persistence of allergies:

“Allergic rhinitis (AR) is a common IgE-mediated disorder involving troublesome symptoms of nasal congestion, nasal itch, sneezing, and associated eye symptoms. Like many chronic health conditions, AR stems from complex gene–environment interactions.

130 subjects with AR were recruited. Control population included 154 healthy children who underwent a regular physical examination in the same ear, nose and throat clinic as AR patients. Individuals with history of asthma or atopic dermatitis were excluded.

AR analysis

Plenty of contradictory associations exist as whether furred pet exposure (cats and dogs) may be a risk or a protective factor for AR development. Discrepancies are likely due to the ubiquitous nature of pet allergens, while pet owners are more concerned about sanitation and many other hygiene-related reasons.

Interaction of early-life pet exposure with methylation level of ADAM33 increased the risk for AR onset 1.423 times more in children. This study provides evidence that:

  • Early-life pet exposure and low methylation level of ADAM33 increase AR risk in children; and
  • The interaction between pet exposure and methylation level of ADAM33 may play an important role in development of AR.”

https://aacijournal.biomedcentral.com/articles/10.1186/s13223-021-00526-5 “Interaction between early-life pet exposure and methylation pattern of ADAM33 on allergic rhinitis among children aged 3–6 years in China”


There’s nothing children can do about who their parents were. Exposing them to pet allergens, though, may be another example of early-life experiences causing lifelong effects.

Week 56 of Changing to a youthful phenotype with sprouts

1. Per Improving healthy compounds of broccoli sprouts and Broccoli sprouts’ immune effects, this week I added mustard sprouts and red cabbage sprouts to my twice-daily routine of eating 3-day-old microwaved broccoli sprouts.

At first, I started mustard and red cabbage seeds with the same 10.7 gram weight (one tablespoon) of seeds. They grew well such that after three days, mustard sprouts weighed an average 61.2 g, and red cabbage sprouts weighed 60.3 g average. Both of these were slightly less than broccoli sprouts’ 65.5 g average.

3-day-old mustard sprouts substantially mellowed out from mustard seeds’ effects. After microwaving mustard sprouts to ≤ 60°C (140°F) and letting them sit for five minutes, I still felt constant nose burn while eating them. 3-day-old red cabbage sprouts were milder than broccoli sprouts, so no difficulties.

The main problem with doing one tablespoon seed weights of all three Brassicaceae species consistently was that 61.2 + 60.3 + 65.5 = 187 g (6.6 ounces) twice a day was too much for me. I eat a lot of low-calorie fibrous food everyday to make my gut microbiota happy. An extra 4+ oz increase at the same time as twice-daily broccoli sprouts put my stomach over the top.

I changed to make equal contents of these three Brassicaceae species be the 10.7 g (one tablespoon) that I started sprouting twice a day.

2. I haven’t seen relevant mustard and red cabbage 3-day-old sprout studies, only 7+ day microgreen and mature plant studies. Evidence is limited in determining effects of cutting my estimated 52 mg of daily sulforaphane intake from broccoli sprouts by two-thirds starting this week.

A. I’ve eaten a clinically-relevant amount of sulforaphane every day for 4+ times longer than any clinical trial. I’ve experienced many positive effects described in studies, and look forward to further improvements.

Reducing sulforaphane intake from broccoli sprouts to 17 mg is still within boundaries of measurable effects. As an example, Upgrade your brain’s switchboard with broccoli sprouts found effects from a daily sulforaphane 17.3 mg (100 µmol) intake.

B. Mustard’s main glucosinolate, sinigrin, hydrolyzes to allyl isothiocyanate, and is in the same aliphatic group as broccoli’s glucoraphanin, which hydrolyzes to sulforaphane. An example of their similar effects was in a citation of Eat broccoli sprouts for DIM:

“Isothiocyanates are both inducers and substrates for Phase II enzymes as glutathione-S-transferases, and polymorphisms of these enzymes have a significant impact.”

Mustard’s myrosinase enzyme activities over and above broccoli myrosinase were highlighted in cited studies of Does sulforaphane reach the colon? Pretty sure that mustard sprouts’ myrosinase ≤ 60°C increases broccoli sprouts’ sulforaphane.

C. Red cabbage’s main glucosinolate is also glucoraphanin. Here’s a graphic from a 2010 study RED CABBAGE, A VEGETABLE RICH IN HEALTH-RELATED GLUCOSINOLATES which compared its glucoraphanin content with white cabbage:

red cabbage glucoraphanin vs white cabbage

The seeds I received were an “Agnostic” variety. In clarification correspondence with my supplier, I received a response “It means in this use ‘Generic’ or Variety not stated. Meaning it is just whatever variety of Red cabbage we bought and we don’t know the exact specifics.” 🙄

Red cabbage anthocyanins have a larger extent than broccoli anthocyanins, which was highlighted in Colorize your diet, Red cabbage pigments and the brain, and Measuring bioavailability. Figure 5 of Lab analyses of broccoli sprout compounds had analysis of three red cabbage cultivars’ 9-day-old sprouts. Glucosinolates are on top, hydrolysis products on the bottom. Glucoraphanin is red 4MSOB in A, and sulforaphane is red 4MSOB-ITC in C:

red cabbage 9-day-old sprouts

D. In summary, I don’t think I’ve significantly reduced broccoli sprouts’ effects by substituting two-thirds weight with two other Brassicaceae species. I haven’t noticed that growth characteristics / compounds interfered with each other.

Still looking for mustard and red cabbage 3-day-old sprout studies. My current Brassicaceae species composite is tasty, and doesn’t cause mustard nose burn.

3. This Brassicaceae species composite isn’t photogenic:

PXL_20210502_214348538

Red cabbage sprouts by themselves are pretty.

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4. I still eat 3-day-old oat sprouts twice a day per Sprouting hulled oats. I don’t eat them with Brassicaceae species, but wait at least an hour later with Avena nuda oats in the morning, and AGE-less chicken vegetable soup in the evening.

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.

An overlooked gut microbiota product

This 2021 review subject was histone crotonylation:

“Histone crotonylation is a newly identified epigenetic modification that has a pronounced ability to regulate gene expression. It belongs to an expanding group of short chain lysine acylations that also includes the extensively studied mark histone acetylation.

Histone Kcr was first identified in 2011 where it was found to be mainly associated with active chromatin. Kcr occurs on the ε-amino group of the lysine side chain, where it neutralizes the positive charge of this residue. The loss in positive charge on histone Lys residues weakens DNA interaction, thus making chromatin less compact and accessible to DNA-binding factors.

Crotonate, like other short chain fatty acids (SCFAs), is mainly produced by gut microbiota during fermentation of partially and nondigestible carbohydrates. Circulating SCFAs (acetate, crotonate, butyrate, and propionate) can be taken up by tissues and converted into their cognate short-chain acyl-CoAs, the direct donors of histone Lys acylations.

fcell-09-624914-g001

Crotonyl-CoA is generated as a by-product of fatty acid and amino acid metabolism. Synthesis of crotonyl-CoA can occur in mitochondria or the cytoplasm. Evidence suggests that histone acylations are directly sensitive to changes in concentrations of their corresponding acyl-CoA metabolites, and therefore can act as indicators of cellular metabolic state.

Only a small number of Kcr sites in human histones have been identified so far. This is in part due to a lack of commercially available Kcr site-specific antibodies, which has meant much of the research in this field has focused on studying total histone crotonylation. This is likely to limit our understanding of the importance of histone Kcr, as functional impact of modification at specific sites cannot be readily assessed.”

https://www.frontiersin.org/articles/10.3389/fcell.2021.624914/full “The Regulation and Function of Histone Crotonylation”


At first I thought I had missed recent studies of gut microbiota producing crotonate. Searching again for “crotonate” “microbiota” 2020 2021, I didn’t find any that weren’t cited by this paper.

A lack of research could be due to factors mentioned above. It may also be that researchers just don’t look for evidence of the circulating SCFA crotonate.

Broccoli sprouts’ immune effects

Two 2021 papers, with the first’s subject being sulforaphane’s immune effects:

“Effects of sulforaphane (SFN) on immune response generate scientific interest because of its bioavailability, which is much higher than other phytochemicals, and its capacity to induce Nrf2 target genes. Clinical trials suggest that sulforaphane produces favorable results in cases where pharmaceutical products fail.

SFN exhibits the highest bioavailability among well-known antioxidant phytochemicals, such as quercetin (20-fold higher) and curcumin (80-fold higher). SFN confers a high potential to be used either as a nutraceutical to improve health status, or as pharmaceutical to treat disease states.

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Sulforaphane exerts a pleiotropic effect on immunological response, and the final effect depends on cell type.

  • In lymphocyte T-cells, SFN induces ROS production, GSH depletion, and repression of inflammatory cytokines, resulting in suppression of immune and inflammatory responses.
  • In monocytes and macrophages, SFN stimulates immune response by inducing Nrf2, thus triggering antioxidant and anti-inflammatory responses.”

https://www.mdpi.com/1420-3049/26/3/752/htm “Potential of Sulforaphane as a Natural Immune System Enhancer: A Review”


A second study was Fertilization and Pre-Sowing Seed Soaking Affect Yield and Mineral Nutrients of Ten Microgreen Species:

“Ten tested microgreen species [amaranth, arugula, basil, broccoli, red cabbage, Daikon radish, kale, kohlrabi, mustard, and green pea] in this study varied in fresh and dry shoot weights, shoot height, and mineral nutrient concentrations.”

This study grew sprouts for 6 – 18 days before harvesting. Its study design didn’t require sampling along the way to discover informative compositional changes, as did 2020’s 3-day-old broccoli sprouts have the optimal yields and Broccoli sprout compounds include sinapic acid derivatives.

Their supplier was the same as I used for broccoli and red cabbage seeds. No endorsement is intended.

I’d rather use an unknown broccoli variety than this study’s broccoli cultivar, Waltham 29. It was found to be relatively glucoraphanin-deficient when measured in a 2004 study referenced in Tailoring measurements for broccoli sprouts, 32nd of 34 tested.

Received these today:

PXL_20210424_191628875

I’ve asked for clarification of the red cabbage seed variety I received. Not sure what “Agnostic” means in a “Red Cabbage Microgreen – Agnostic” context. 🙂

Mustard and red cabbage sprouting will follow Improving healthy compounds of broccoli sprouts efforts, minus that study’s laboratory setup and duration. I expect synergistic effects from handling both species’ sprouts with my protocol for microwaved 3-day-old broccoli sprouts.

Benefits of eating fermentable fiber

This 2021 review subject was effects of short-chain fatty acids produced by gut microbiota:

“SCFAs are the main players in the interplay between diet, microbiota, and health. SCFAs contribute to intestinal homeostasis and regulation of energy metabolism.

SCFAs regulate the blood–brain barrier and neuroimmunoendocrine functions. During gestation, SCFAs can cause epigenetic imprinting and protect against allergic airway disease.

gr3_lrg

Fiber reaching the colon is anaerobically fermented by gut bacteria, which produce SCFAs. Nondigestible polysaccharides are found in plant cell walls, and are further classified into soluble and nonsoluble dietary fibers.

A role for SCFAs in histone modification of tissues in the body was definitively shown by dietary supplementation of germ-free mice with microbially produced acetate, propionate, and butyrate. These SCFAs increased acetylation of histone H4 and H3 in a tissue-specific fashion.

Most research to date has focused on butyrate but unlike acetate and propionate, it is typically present in undetectable or very low concentrations in the body. SCFAs appear to influence health through three principal mechanisms:

  1. Altering levels of HAT [histone acetyltransferase] and HDAC [histone deacetylase] activity;
  2. Signaling by specific fatty acid-sensing GPCRs [G-protein-coupled receptors]; and
  3. Anti-inflammatory mechanisms in the periphery and tissues due to the first two mechanisms.”

https://www.cell.com/trends/microbiology/fulltext/S0966-842X(21)00035-4 “Microbial Regulation of Host Physiology by Short-chain Fatty Acids”


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Effects of another broccoli sprout compound

This 2020 rodent study investigated effects of broccoli sprout hydrolysis compound indole-3-carbinol:

“I3C metabolites act as ligands of the aryl hydrocarbon receptor (AhR), an important sensor for environmental polyaromatic chemicals. We investigated how dietary AhR ligand supplementation influences AhR target gene expression and intestinal microbiota composition.

Environmental signals, such as dietary, microbial, or xenobiotic factors, are sensed in intestinal tissue AhR, an important regulator of metabolism. It influences immune cell homeostasis and immune activation in the intestine.

AhR activation plays an important role in intestinal immunity, contributing to intestinal homeostasis, inflammation, and host defense:

  • AhR activation through high affinity AhR ligands has been shown to stimulate production of antimicrobial peptides.
  • AhR has been shown to be an important regulator of T cell immunity.

This indicates a major role of AhR in resolving intestinal inflammation.

High fat diet and control diet lead to reduced expression of Ahrr in intestinal immune cells.

High fat diet and control diet lead to reduced expression of Ahrr in intestinal immune cells.

Mucosal surface area of the gut represents an enormous area in direct contact with the environment. In addition to occasional pathogen encounters, the intestinal immune system is constantly exposed to antigens from diet or microbiota.

Gut-associated immune cells maintain a balance between protection against harmful infections and tolerating harmless food-derived antigens and commensals.

Our findings are in agreement with reports that dietary I3C supplementation restored AhR activation in intestinal mucosa under conditions of malnutrition and deprivation of natural AhR ligands. In humans, such malnutrition may result from a severely reduced consumption of vegetables and fruit in favor of a carbohydrate rich, high fat diet.”

https://www.mdpi.com/1422-0067/21/9/3189/htm “Dietary AhR Ligands Regulate AhRR Expression in Intestinal Immune Cells and Intestinal Microbiota Composition”


Our gut microbiota outnumber our human cells. Treat them well with broccoli sprout compounds, resistant starch, and fermentable fibers, and expect reciprocity.

Every hand’s a winner, and every hand’s a loser

Another great blog post Know When To Fold ‘Em by Dr. Paul Clayton:

“Newly formed proteins entering the endoplasmic reticulum must be correctly folded to achieve their final form and function. This is a complex procedure with a failure rate of over 80%.

When metabolism is sufficiently skewed, accuracy of protein folding in the endoplasmic reticulum falls below an already low baseline of 20%. Accumulation of misfolded or unfolded proteins in the endoplasmic reticulum then triggers stress.

Integrated Stress Response (ISR) is something that cells do when they are affected by major stressors:

  • ISR turns down global protein synthesis, which is designed to kill virally infected or cancerous cells. If it kills the cancer cell or virally infected cell, that is the end of it.
  • If the stressor is in the heat / hypoxia / nutrient group, however, ISR effectively puts a cell into dark mode until hard times are over. Once the stressor has passed, a cell can then start to recover and return to homeostatic health.
  • But if the stressor is sustained, a low-grade ISR continues to smolder away, causing long-term impairment locally and ultimately systemically. Accumulation of misfolded or unfolded proteins activates ISR, leading to a down-regulation of protein synthesis, and increasing protein folding and degradation of unfolded proteins.

This is analogous to inflammation. Acute inflammatory responses to a pathogen or to tissue damage are entirely adaptive, and essential. Chronic inflammation, on the other hand, causes local and eventually systemic damage if left unchecked for long enough.”


A 2020 rodent study was cited for “reversing age-related cognitive decline”:

“This suggests that the aged brain has not permanently lost cognitive capacities. Rather, cognitive resources are still there, but have been somehow blocked, trapped by a vicious cycle of cellular stress.

Our work with ISR inhibition demonstrates a way to break that cycle, and restore cognitive abilities that had become walled off over time.

stress response inhibitor effects

If these findings in mice translate into human physiology, they offer hope and a tangible strategy to sustain cognitive ability as we age.”

https://elifesciences.org/articles/62048 “Small molecule cognitive enhancer reverses age-related memory decline in mice”


I’m curious as to why sulforaphane hasn’t been mentioned even once in Dr. Paul Clayton’s blog, which started three years ago. Do hundreds of sulforaphane studies performed in this century not contribute to his perspective? Polyphenols are mentioned a dozen times, yet they are 1% bioavailable compared with 80% “small molecule” sulforaphane.

Advice from the song depends on your definition of money:

“Know when to walk away
Know when to run
Never count your money
When you’re sitting at the table”

Improving healthy compounds of broccoli sprouts

This 2020 study investigated known and experimental effects on sprouted broccoli, white mustard, red radish, and red cabbage compounds:

“We planned development of cruciferous sprouts in hydroponics elicited with LED lighting and Methyl-Jasmonate (MeJA) to bio-stimulate production of glucosinolates, comparing effects of two types of LEDs designed for indoor food production systems.

We aimed to gain knowledge on response (germination rate, biomass yield) and phytochemical composition of fresh edible sprouts of cruciferous varieties (broccoli, radish, cabbage and mustard) under these conditions for future food production recommendations:

  • Use of LED lights to grow edible cruciferous sprouts was positive in terms of biomass production and phytochemical content (glucosinolates) without any negative effects.
  • Use of MeJA was positive, confirming previous results. Intensity of response for different species is useful to focus production of sprouts for specific purposes.

3-day old sprouts were placed in a growth chamber with controlled conditions (Photoperiod 18/6 h; temperature 24/18 °C; and relative humidity 60/80%), irrigated every other day to maintain enough humidity in substrate, using 1% bleach in distilled water, and collected on day 7. Trays of germinating seeds were evenly sprayed daily with 10 mL of solution for 4 days.

4 sprouts glusosinolates affected by LED and MeJa

Total Glucosinolates (mg/100 g fresh weight) of White Mustard, Broccoli, Red Cabbage and Red Radish sprouts, under two different LED lightings, and elicited with MeJA (250 μM).

Combining MeJA spraying with different LED light treatment showed clear increases in total glucosinolate contents for all studied sprouts when sprayed for 4 days with MeJA 250 μM.”

https://www.mdpi.com/2504-3900/70/1/67 “The Quality and Glucosinolate Composition of Cruciferous Sprouts under Elicitor Treatments Using MeJA and LED Lights”


The research group of Our model clinical trial for Changing to a youthful phenotype with broccoli sprouts keep ramping it up. They’ve published studies of MeJA effects and LED effects on sprouts separately, but not combined like this one did.

I ordered a pound of red cabbage seeds to see how I like their 3-day-old sprouts. I started soaking mustard seeds purchased from a grocery store’s spice section last year to see if they’ll sprout.

Although effects in the above graphic are compelling, I don’t want to turn my kitchen into a laboratory with LED lights and MeJA treatments. I’ll first see if red cabbage and mustard sprouts are tolerable.

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.

PXL_20210412_104353167

Repositioning DNA methylation

This 2021 human study found:

“We report on a randomized controlled clinical trial conducted among 43 healthy adult males between the ages of 50-72. The 8-week treatment program included diet, sleep, exercise and relaxation guidance, and supplemental probiotics and phytonutrients.

This is the first randomized controlled study to suggest that specific diet and lifestyle interventions may reverse Horvath DNAmAge (2013) epigenetic aging in healthy adult males. Larger-scale and longer duration clinical trials are needed to confirm these findings, as well as investigation in other human populations.

aging-v13iundefined-202913-figure-f3

In both treatment and control groups, there was no net increase or decrease in methylation of 353 sites that compose the Horvath clock. This finding suggests that intervention did not lead to an overall increase in methylation of Horvath clock sites, but rather it prompted a repositioning of clock CpG methylation patterns consistent with a younger biological age.

One significant limitation of this pilot trial is limited statistical power due to relatively small sample size. It is not yet fully established whether interventions that slow any methylation clocks necessarily curtail risks of age-related disease.”

https://www.aging-us.com/article/202913/text “Potential reversal of epigenetic age using a diet and lifestyle intervention: a pilot randomized clinical trial”


Baffled as to why these researchers relied on 2013 research rather than at least Dr. Horvath’s improved 2018 skin and blood clock, a review of which noted:

“Although the skin-blood clock was derived from significantly less samples (~900) than Horvath’s clock (~8000 samples), it was found to more accurately predict chronological age, not only across fibroblasts and skin, but also across blood, buccal and saliva tissue. A potential factor driving this improved accuracy in blood could be related to the approximate 18-fold increase in genomic coverage afforded by using Illumina 450k/850k beadarrays.”

Which would you prefer? A 2013 flip phone, or a 2018 smartphone?

A bat epigenetic clock

This 2021 study subject was bats:

“Exceptionally long-lived species, including many bats, rarely show overt signs of aging, making it difficult to determine why species differ in lifespan. Here, we use DNA methylation (DNAm) profiles from 712 known-age bats, representing 26 species, to identify epigenetic changes associated with age and longevity.

Hypermethylated age- and longevity-associated sites are disproportionately located in promoter regions of key transcription factors (TF) and enriched for histone and chromatin features associated with transcriptional regulation. Predicted TF binding site motifs and enrichment analyses indicate that:

  • Age-related methylation change is influenced by developmental processes, while
  • Longevity-related DNAm change is associated with innate immunity or tumorigenesis genes, suggesting that
  • Bat longevity results from augmented immune response and cancer suppression.

Molossus molossus [a short-lived species] age genes are not enriched for immunity genes or genes that frequently mutated in cancer. However, M. molossus longevity genes exhibit significant overlap with genes involved in immunity and genes frequently mutated in human tumors.

Similar overlap patterns among immunity, longevity, and tumor-mutated genes also exist for long-lived bats.

Two species’ genetic adaptations for tumor suppression have been described to help explain their extreme longevity. Bats also have genetic mechanisms that enable strong antiviral immune responses without inducing damaging inflammatory reactions that may enable them to tolerate high levels of viral exposure.

Our results are consistent with an epigenetic clock theory of aging that connects beneficial developmental and cell maintenance processes to detrimental processes causing tissue dysfunction.”

https://www.nature.com/articles/s41467-021-21900-2 “DNA methylation predicts age and provides insight into exceptional longevity of bats”


The founder of the epigenetic clock has been busy, coauthoring more published studies than there have been weeks in this year! I’ve read five other 2021 studies he’s coauthored on dogs, horses, mammals (2), and humans in DNA methylation biomarker for cumulative lead exposure is associated with Parkinson’s disease. This one stood out for its “longevity results from augmented immune response and cancer suppression” findings.

If we’re interested in longevity, this clarity can direct efforts to both improve our immune systems and avoid problems like cancer. Symptoms may be subclinical, but that doesn’t provide adequate rationale to not address causes.

Peer review comments and responses were informative:

Reviewer #1 – “Developing an aging clock that works for a diverse set of bat species is a spectacular achievement.”

Reviewer #2 – “This is a tour de force study.”

Replies to Reviewer #3:

“Difference in recorded lifespans between three long-lived species and two short-lived species that we used to identify longevity DMPs [differentially methylated positions] is 20 years or more, even though they have similar body sizes (20-40 g). The three long-lived species [maximum ages 29.9, 30.5, and 37.1 years] also represent three different phylogenetic lineages.

CpG sites that undergo hypomethylation with age do so largely at random. In contrast, sites that undergo hypermethylation with age are highly nonrandom, and as has been noted before, are near genes associated with development. So yes, we believe there are predictable methylation changes with age.”

Train your gut microbiota with taurine

This 2021 rodent study found:

“We show that gut microbiota from previously infected hosts display enhanced resistance to infection. This long-term functional remodeling is associated with altered bile acid metabolism leading to expansion of taxa that utilize taurine.

Supplying exogenous taurine alone is sufficient to induce this alteration in microbiota function and enhance resistance. Taurine potentiates microbiota production of sulfide, an inhibitor of cellular respiration, which is key to host invasion by numerous pathogens.

fx1_lrg

This work reveals a process by which the host, triggered by infection, can deploy taurine as a nutrient to nourish and train microbiota, promoting its resistance to subsequent infection.”

https://www.cell.com/cell/fulltext/S0092-8674(20)31681-0 “Infection trains the host for microbiota-enhanced resistance to pathogens” (not freely available)


News coverage added:

“The studied infections induced host taurine production and expansion of taurine utilizers. Taurine was the trigger for activity of a class of bacteria that fight these infections.

The group’s data suggest that low levels of taurine allow pathogens to colonize the gut, but high levels produce enough hydrogen sulfide to prevent colonization. Taurine given to mice in drinking water prepared microbiota to prevent infection. However, when mice drank water containing bismuth subsalicylate, a common over-the-counter drug used to treat diarrhea and upset stomach, infection protection waned because bismuth inhibits hydrogen sulfide production.”

Can’t calculate a human equivalent dose without access to this study. I take 1 gram of taurine twice a day.

Per Treating psychopathological symptoms will somehow resolve causes? I resumed taurine supplementation last year after taking a year’s break. From that paper’s taurine section:

“Most studies that reported enhanced GSH [glutathione] 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.”

If that paper’s hypothesis is correct, and the current study’s evidence is replicable, taurine supplementation is a win-win for both our brain and gut microbiota.


Sunrise minus 5 minutes

Let β-glucan train your brain

This 2021 rodent study investigated yeast cell wall β-glucan’s effects on the brain’s immune system:

“Innate immune memory can manifest in two different ways, [1] immune training and [2] immune tolerance, which means [1] an enhanced or [2] suppressed immune response towards a secondary challenge. Lipopolysaccharide (LPS) and β-glucan (BG) are two commonly used ligands to induce immune training and tolerance.

Microglia, the innate immune cells of the central nervous system, can adopt diverse phenotypes and functions in health and disease. In our previous study, we have shown that LPS preconditioning induces immune tolerance in microglia.

Compared to LPS, relatively little is known about effects of BG on microglia. In this study, we report for the first time that systemic administration of BG activates microglia in vivo, and that BG preconditioning induces immune training in microglia.

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Our results show that BG activated microglia without inducing significant cytokine expression.

BG- and LPS-preconditioning both induced immune training in microglia two days after the first challenge. However, with an interval of 7 days between the first and second challenge, LPS-preconditioning induced immune tolerance in microglia where BG-induced immune training was no longer detected.”

https://jneuroinflammation.biomedcentral.com/articles/10.1186/s12974-021-02103-4 “Systemic administration of β-glucan induces immune training in microglia”


One solution to “BG-induced immune training was no longer detected” after 7 days is to take β-glucan every day. I haven’t seen studies that found β-glucan induced immune tolerance, i.e. “suppressed immune response towards a secondary challenge.”

I take allergy medicine twice a day. Switched over to a different β-glucan vendor and dose per Year One of Changing to a youthful phenotype with broccoli sprouts.

I take 1 gram of Glucan 300 capsules without eating anything an hour before or an hour afterwards. I’ve only been doing it for a week, though, and haven’t been able to separate out β-glucan effects on seasonal allergies. I’ll try stopping allergy medicine when pollen stops coating my car.

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Swarming a spring sea trout run. Ospreys outcompeted gulls for breakfast.