Gut microbiota topics

Here are thirty 2019 and 2020 papers related to Switch on your Nrf2 signaling pathway topics. Started gathering research on this particular theme three months ago.

There are more researchers alive today than in the sum of all history, and they’re publishing. I can’t keep up with the torrent of interesting papers.

on

2020 A prebiotic fructo-oligosaccharide promotes tight junction assembly in intestinal epithelial cells via an AMPK-dependent pathway

2019 Polyphenols and Intestinal Permeability: Rationale and Future Perspectives

2020 Prebiotic effect of dietary polyphenols: A systematic review

2019 Protease‐activated receptor signaling in intestinal permeability regulation

2020 Intestinal vitamin D receptor signaling ameliorates dextran sulfate sodium‐induced colitis by suppressing necroptosis of intestinal epithelial cells

2019 Intestinal epithelial cells: at the interface of the microbiota and mucosal immunity

2020 The Immature Gut Barrier and Its Importance in Establishing Immunity in Newborn Mammals

2019 Prebiotics and the Modulation on the Microbiota-GALT-Brain Axis

2019 Prebiotics, Probiotics, and Bacterial Infections

2020 Vitamin D Modulates Intestinal Microbiota in Inflammatory Bowel Diseases

2020 Microbial tryptophan metabolites regulate gut barrier function via the aryl hydrocarbon receptor

2019 Involvement of Astrocytes in the Process of Metabolic Syndrome

2020 Intestinal Bacteria Maintain Adult Enteric Nervous System and Nitrergic Neurons via Toll-like Receptor 2-induced Neurogenesis in Mice (not freely available)

2019 Akkermansia muciniphila ameliorates the age-related decline in colonic mucus thickness and attenuates immune activation in accelerated aging Ercc1−/Δ7 mice

2020 Plasticity of Paneth cells and their ability to regulate intestinal stem cells

2020 Coagulopathy associated with COVID-19 – Perspectives & Preventive strategies using a biological response modifier Glucan

2020 Synergy between Cell Surface Glycosidases and Glycan-Binding Proteins Dictates the Utilization of Specific Beta(1,3)-Glucans by Human Gut Bacteroides

2020 Shaping the Innate Immune Response by Dietary Glucans: Any Role in the Control of Cancer?

2020 Systemic microbial TLR2 agonists induce neurodegeneration in Alzheimer’s disease mice

2019 Prebiotic supplementation in frail older people affects specific gut microbiota taxa but not global diversity

2020 Effectiveness of probiotics, prebiotics, and prebiotic‐like components in common functional foods

2020 Postbiotics-A Step Beyond Pre- and Probiotics

2019 Pain regulation by gut microbiota: molecular mechanisms and therapeutic potential

2020 Postbiotics: Metabolites and mechanisms involved in microbiota-host interactions

2020 Postbiotics against Pathogens Commonly Involved in Pediatric Infectious Diseases

2019 Glutamatergic Signaling Along The Microbiota-Gut-Brain Axis

2019 Lipoteichoic acid from the cell wall of a heat killed Lactobacillus paracasei D3-5 ameliorates aging-related leaky gut, inflammation and improves physical and cognitive functions: from C. elegans to mice

2020 Live and heat-killed cells of Lactobacillus plantarum Zhang-LL ease symptoms of chronic ulcerative colitis induced by dextran sulfate sodium in rats

2019 Health Benefits of Heat-Killed (Tyndallized) Probiotics: An Overview

2020 New Horizons in Microbiota and Metabolic Health Research (not freely available)

Oat species comparisons of the good stuff

This 2020 study compared and contrasted distributional compositions of two oat species’ seeds:

“Oat grains of one hulless variety (Lamont) with low avenanthramide (AVA) contents and one hulled variety (Reins) with high AVA contents were sequentially abraded. Contents of nutrients (protein, oil, starch, β-glucan, ash, and other carbohydrates) and AVAs were measured.

A relationship between content of a constituent in the surface layer abraded off (termed pearling fine, or PF) at each cycle of pearling and the cumulative level of surface removal could be established. This relationship essentially describes true distribution or localization of individual constituents across an oat kernel.

AVAs provide health benefits in mammals, including anti-oxidation, anti-inflammation, anti-atherosclerosis, and anti-cancer properties. Relationships between contents of four AVAs and total AVAs in pearling fines (A) and corresponding pearled kernels (B) of hulless Lamont oat [top] and hulled Rein [bottom] with cumulative surface removal levels achieved by sequential pearling:

For Lamont oat, AVAs 2c, 2f, 2p, 5p, and total AVAs all showed decreasing concentrations with increasing levels of surface removal. The first PF (4% surface removal) contained the highest amounts for all four AVAs, with 2p near ten times higher than in whole grain.

Hulled Reins oat differed significantly from hulless Lamont oat in not only amounts of AVAs but also their distribution patterns within kernels. Dehulling caused reduction in total AVA content.

Pearled oats contained less protein, oil, ash, and other carbohydrates and AVAs, but more starch than whole grain. In contrast, oat bran contained more AVAs, protein, oil, ash and other carbohydrates but less β-glucan and starch as compared to whole grain.”

https://www.sciencedirect.com/science/article/abs/pii/S0308814620315302 “Distributions of nutrients and avenanthramides within oat grain and effects on pearled kernel composition” (not freely available)


There were higher AVA contents in hulls of the top graphic’s species (Avena nuda) compared with its next ten seed layers. Humans require the bottom graphic’s oat species’ (Avena sativa) hull, which is “about 25% total grain mass,” to be milled off before we eat it. So AVA data points on the bottom graph A start around 25% surface removal.

As mentioned in Eat oats to prevent diabetes, I replaced steel-cut Avena sativa oats with whole Avena nuda oats for breakfast. I don’t know how well Avena nuda hulls are digested, but gut microbiota ferment similar indigestibles into beneficial compounds.

The first study of Eat oat sprouts for AVAs found “up to 25-fold increase” in AVAs with 7-day-old Avena sativa sprouts. I expect 3-day-old hulled Avena sativa sprouts I eat also increase AVAs as they germinate.

Our first 1000 days

This 2021 review subject was a measurable aspect of our early lives:

“The first 1000 days from conception are a sensitive period for human development programming. During this period, environmental exposures may result in long-lasting epigenetic imprints that contribute to future developmental trajectories.

The present review reports on effects of adverse and protective environmental conditions occurring on glucocorticoid receptor gene (NR3C1) regulation in humans. Thirty-four studies were included.

The hypothalamic-pituitary-adrenal (HPA) axis is key in regulating mobilization of energy. It is involved in stress reactivity and regulation, and it supports development of behavioral, cognitive, and socio-emotional domains.

The NR3C1 gene encodes for specific glucocorticoid receptors (GRs) in the mammalian brain, and it is epigenetically regulated by environmental exposures.

When mixed stressful conditions were not differentiated for their effects on NR3C1 methylation, no significant results were obtained, which speaks in favor of specificity of epigenetic vestiges of different adverse conditions. Specific maternal behaviors and caregiving actions – such as breastfeeding, sensitive and contingent interactive behavior, and gentle touch – consistently correlated with decreased NR3C1 methylation.

If the neuroendocrine system of a developing fetus and infant is particularly sensitive to environmental stimulations, this model may provide the epigenetic basis to inform promotion of family-centered prevention, treatment, and supportive interventions for at-risk conditions. A more ambiguous picture emerged for later effects of NR3C1 methylation on developmental outcomes during infancy and childhood, suggesting that future research should favor epigenome-wide approaches to long-term epigenetic programming in humans.”

https://www.sciencedirect.com/science/article/abs/pii/S0149763421001081 “Glucocorticoid receptor gene (NR3C1) methylation during the first thousand days: Environmental exposures and developmental outcomes” (not freely available). Thanks to Dr. Livio Provenci for providing a copy.


I respectfully disagree with recommendations for an EWAS approach during infancy and childhood. What happened to each of us wasn’t necessarily applicable to a group. Group statistics may make interesting research topics, but they won’t change anything for each individual.

Regarding treatment, our individual experiences and needs during our first 1000 days should be repeatedly sensed and felt in order to be therapeutic. Those memories are embedded in our needs because cognitive aspects of our brains weren’t developed then.

To become curative, we first sense and feel early needs and experiences. Later, we understand their contributions and continuations in our emotions, behavior, and thinking.

And then we can start to change who we were made into.

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.

Sprouting hulless oats

I finished a 3-lb. bag of hulled Avena sativa oats used in Sprouting hulled oats after starting 20 gram batches twice a day. Amazon said that Montana farmer’s products were “Currently unavailable. We don’t know when or if this item will be back in stock.” I went to their website and emailed an inquiry.

Turns out it’s Amazon’s problem in restocking pallets that are already received! I placed an order directly with the farmer.

In the meantime, I’m trying another oat species, Avena nuda, from an Illinois farmer. I’ll reuse Degree of oat sprouting as the model, since it was also an Avena nuda oat variety.

  • Oat seed size was 7-9 mm x 2-3 mm. The model used “huskless oat ‘Gehl’” which may be a different variety.
  • 100 seeds weighed 2.9 grams. There were close to 700 seeds per 20 g batches.
  • Oat sprout batches were processed the same way I do broccoli sprout batches. A new batch started soaking to start germination every 12 hours, then was rinsed three times every 24 hours on a 6 hours – 6 hours – 12 hours cycle.
  • Temperature in my kitchen was 21°C (70°F) because it’s snowing outside. The model findings included “Temperatures between 20° and 25°C yielded the most dramatic changes in properties of sprouted oats.”

I evaluated germination results per the model’s Degree of Sprouting finding:

“Length of the coleoptile [shoot] was selected as a criterion of categorization of degree of sprouting. Grains of degree 0 do not show any radicle [root] or coleoptile growth. Degree:

  1. Has visible embryos (small white point), while radicles and coleoptile are not visible;
  2. Shows a developed embryo emerging from the seed coat;
  3. Coleoptile lengths of at least half the oat grain length;
  4. Coleoptile lengths between half and a full grain length; and
  5. Coleoptile longer than a full grain length.”

Here’s what this hulless oat variety’s seeds and 3-day-old sprouts looked like:

The tedious part was evaluating degrees of sprouting. I took as large a bottom-to-top sample as I could tolerate sorting (160 seeds / sprouts, about 23%), with these results:

A 91% germination rate. 🙂 Average weight of 3-day-old batches was 42.5 grams, for a 213% weight gain. That wasn’t as much as 3-day-old hulled oats’ 97% germination rate and 260% weight gain.

For degree-of-sprouting comparisons, here are my eyeball estimates of the model study’s 3-day-old hulless oats:

These 3-day-old hulless oat sprouts taste starchier with less enzyme aftertaste than 3-day-old hulled oat sprouts. Will extending their growth to four days increase degree-of-sprouting categories 4 and 5, and change their taste?

An extra day from 5 to 6 didn’t make a difference in Sprouting whole oats germination rate. I don’t expect non-germinated percentages to change from 3 to 4 days, but we’ll see.

I expect similar overall increases in antioxidants, GABA, phenolic compounds, protein, amino acids, β-glucan, and polyunsaturated fatty acids as hulled oat sprouts.

Update: Four-day-old hulless oat sprouts have a little more sweetness and enzyme aftertaste. Their degree-of-sprouting and germination rate didn’t change much, though. I’ll stick with four days for this variety.

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)

Part 2 of Sprouting hulled oats

In Sprouting hulled oats, seeds were sprouted at 21°C (70°F) for 3 days. That post ended with a question raised by Oat sprouts analysis regarding desirability of enzymes.

Here’s that study’s analysis of its hulled oat variety’s enzymes, excluding results not pertinent to this post. There was neither a 72-hour measurement period nor a 20°C 60-hour period analyzed. Interpolate measurements accordingly.

1. α-amylase enzyme was described as:

“Alpha-amylase plays a key role during germination since it catalyzes hydrolysis of α-1,4 glucosidic linkages of starch, yielding maltose and glucose necessary for seedling development. Activity of this enzyme increased considerably during oat sprouting [reference to Degree of oat sprouting] but it is also de novo synthesized during this process.

High glucose content in sprouted flour can increase its glycemic index (GI). Foods with low GI are beneficial due to low postprandial glucose response compared to foods with a high GI. Selection of germination conditions is crucial to modulate α-amylase activity in oat for obtaining healthier sprouted flours with lower GI.”

A. 3-day-old hulled oat sprouts probably don’t have “High glucose content.” Studies such as Optimization of Oat Amylase During Sprouting to Enhance Sugar Production found:

“Maltose was the primary sugar, though there was a detectable but smaller amount of glucose.”

B. I understand that researchers have adopted a glycemic index. Does that one dimension indexed on glucose at 100 adequately inform health-choice decisions about oat sprout α-amylase enzyme content?

What’s the point of indexing healthy choices like sprouted whole grains to unhealthy choices that healthy people aren’t going to make anyway?

2. Increased protease enzyme activity was analyzed as desirable, and used as an optimization parameter.

3. Lipase activity increased from 18°C 60-hour to 20°C 96-hour measurements in the above graphic. All sprouted oat lipase levels were below unsprouted control oat flour, however:

“Lipase activity decreased in sprouted var. Meeri flour during germination. Our results suggest that there must be an important lipase activity in oat hull.

Lipase hydrolyse triglicerides to free fatty acids that are prone to oxidation and cause rancidity of cereal flours. According to our results, use of dehulled oat grains is desirable to obtain sprouted oat flours with increased stability and longer shelf life.”


Don’t know which enzyme is responsible for mild throat burn after eating 3-day-old hulled oat sprouts. It isn’t unpleasant, just unexpected. Research so far indicates that people pay for catalytic enzymes that increase proteolytic and digestive activity.

What if we index health decisions on a standard at 100 of drinking a beer first thing in the morning? Would anything scaled by that one dimension inform fine tuning of health-choice decisions?

“Woke up this morning and I got myself a beer
The future’s uncertain and the end is always near”

Sprouting hulled oats

My Sprouting whole oats trial was a hassle with hulls and a poor germination rate. This week I used hulled oat seeds from a different vendor, and a different study, Degree of oat sprouting, as my model.

  • Oat variety of Avena sativa was a small seed, 7 mm x 2 mm. The model used “huskless oat ‘Gehl'” which is a different species (Avena nuda).
  • 100 seeds weighed 1.5 grams. There were over 1,300 seeds per 20 g batches.
  • Oat sprout batches were processed the same way I do broccoli sprout batches. A new batch started soaking to start germination every 12 hours, then was rinsed three times every 24 hours on a 6 hours – 6 hours – 12 hours cycle. I have an open question to the model’s corresponding coauthor to explain their “4.5‐hr wet steeping, 19‐hr air rest, and 4‐hr steeping, all at 20°C” procedures to start germination, since I didn’t have access to its cited study. The model grew oat sprouts for 1, 2, and 3 days.
  • Temperature in my kitchen was 21°C (70°F) because it’s winter outside. The model grew oat sprouts at 10, 14, 20, 25, and 30°C. Their findings included “Temperatures between 20° and 25°C yielded the most dramatic changes in properties of sprouted oats.”

I evaluated germination results per the model’s Degree of Sprouting finding:

“Length of the coleoptile [shoot] was selected as a criterion of categorization of degree of sprouting. Grains of degree 0 do not show any radicle [root] or coleoptile growth. Degree:

  1. Has visible embryos (small white point), while radicles and coleoptile are not visible;
  2. Shows a developed embryo emerging from the seed coat;
  3. Coleoptile lengths of at least half the oat grain length;
  4. Coleoptile lengths between half and a full grain length; and
  5. Coleoptile longer than a full grain length.”

Most of this trial wasn’t a big deal, adding just a few extra minutes onto what I do three times a day with broccoli sprouts. Here’s what this oat variety’s hulled seeds and 3-day-old sprouts looked like:

The tedious part was evaluating degrees of sprouting. I took as large a bottom-to-top sample as I could tolerate sorting (235 seeds / sprouts, about 17%), with these results:

A 97% germination rate. 🙂 Average weight of three 3-day-old batches was 51.9 grams, for a 260% weight gain. My 5-day-old whole oat sprouts trial had a 22% germination rate and a 221% weight gain.

The model’s Figure 3 Degree of Sprouting finding for 20°C and 25°C at 3 days was hard to read:

Don’t know how > 1% 0 degrees of sprouting at 20°C and 25°C reconciled with their statement “Germinability after 3 days was about 99% at all temperatures.” A numerical table wasn’t provided – yet another question for the corresponding author. Meanwhile, I’ll estimate:

Their hard-to-read Figure 3 also wasn’t completely congruent with their statement:

“Around 20% of grains sprouted at 20° and 25°C had a coleoptile longer than a full grain length (degree of sprouting 5).”


These oat sprouts tasted milder than my previous trial’s. With more than a third at a degree-of-sprouting 5 measurement, they’re sweet, concurrent with the model’s findings that:

“Increased amounts of reducing sugars and ascorbic acid were found particularly in the radicles and coleoptile. Coleoptile and radicle growth (input parameters for the degree of sprouting) and reducing sugars and α‐amylase activity are interdependent.”

Corresponding increased enzyme concentrations produced an aftertaste, though. I ate them along with either food or drink.

Can eating three-day-old oat sprouts of this Montana cultivated variety help with what I’m already doing? Here’s what I expect, given the model was a different oat species, and the Sprouting oats and Oat sprouts analysis studies used different oat cultivars.

1. In order of magnitude: increased antioxidants, GABA, phenolic compounds, protein, amino acids, β-glucan, and polyunsaturated fatty acids. Don’t know about GABA and protein, but the others may help counter inflammation.

2. Increased enzyme intake. The model study used α-amylase as a marker for α-amylase enzymes (catalyze starches), protease enzymes (catalyze proteins), and lipase enzymes (catalyze fats).

Oat sprouts analysis characterized increased α-amylase and lipase activities as undesirable in a sprouted oat flour context. More on enzymes in Part 2 of Sprouting hulled oats.

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.”


Degree of oat sprouting

This 2019 study investigated oat sprout parameters:

Huskless oat ‘Gehl’ cultivated in 2016 in Canada, was used throughout the study. Grains (500 g) were sprouted at different temperatures (10, 14, 20, 25, and 30°C) and for different times (1, 2, and 3 days). Changes in vitamin C, β‐glucan, and reducing sugar were monitored, and α‐amylase activity was studied as a marker for total enzyme activity.

Mass fraction of radicle [root] and coleoptile [shoot] in grain correlated very well with β‐glucan level. A similarly good correlation was found for the much easier applicable degree of sprouting, visual assessment of coleoptile length set into relation to grain size.

Germinability after 3 days was about 99% at all temperatures. Temperatures between 20° and 25°C yielded the most dramatic changes in properties of sprouted oats.

  • At 3 days, α‐amylase activities at 20° and 25°C increased significantly to values one order of magnitude larger than those for other temperatures.
  • β‐glucan content was decreased after 3 days at all temperatures. Degradation was most pronounced at 20°C, almost halving initial β‐glucan content to 3.9%.
  • No ascorbic acid was present in native grain. Upon sprouting, a significant increase in ascorbic acid content was found – except at 30°C – with highest levels at 20°C.

Ascorbic acid content in radicles and coleoptile was four times higher than that in grain without radicles and coleoptile. Oat grains sprouted for 3 days at 20°C had an average degree of sprouting of 3; hence, radicles and coleoptile contributed about 8% of mass. These findings indicate that a fast visual determination of degree of sprouting allows to estimate, for example, ascorbic acid content without doing expensive experiments.

Around 20% of grains sprouted at 20° and 25°C had a coleoptile longer than a full grain length (degree of sprouting 5). Less long coleoptiles developed at other temperatures.

  • For the 3‐day sprouting period, the longest coleoptile was observed for sprouting at 25°C.
  • At 30°C average degree of sprouting was 1.4, and grains showed no practical radicle growth.

Coleoptile and radicle growth (input parameters for the degree of sprouting) and reducing sugars and α‐amylase activity are interdependent. Degree of sprouting could develop into a reliable characterization method for sprouted grains, usable for predicting compositional and nutritional changes of oats during sprouting.”

https://onlinelibrary.wiley.com/doi/full/10.1002/cche.10203 “Sprouting of oats: A new approach to quantify compositional changes”


Relative humidity wasn’t mentioned in this study. I asked the corresponding coauthor about it, since two Sprouting oats studies stated relative humidity as a factor for sprouting oats.

I also asked them to explain their “4.5‐hr wet steeping, 19‐hr air rest, and 4‐hr steeping, all at 20°C” procedures to start germination, since I didn’t have access to the cited study. No reply yet.

This was my model study for Sprouting hulled oats.

Ducks in a row

A broccoli sprouts study that lacked evidence for human applicability

A 2020 study Combined Broccoli Sprouts and Green Tea Polyphenols Contribute to the Prevention of Estrogen Receptor–Negative Mammary Cancer via Cell Cycle Arrest and Inducing Apoptosis in HER2/neu Mice (not freely available) conclusion was:

“Lifelong BSp [broccoli sprouts] and GTP [green tea polyphenol] administration can prevent estrogen receptor–negative mammary tumorigenesis through cell cycle arrest and inducing apoptosis in HER2/neu mice.”

These researchers had unaddressed insufficiencies in this study that were also in their 2018 study as curated below. The largest item that required translation into human applicability was rodent diet content of 26% “broccoli sprout seeds.”

You may be surprised to read the below previous study’s unevidenced advice to eat double the weight of broccoli sprouts that I eat every day. You won’t be surprised that it’s not going to happen. Especially when no alternatives were presented because rodent diet details weren’t analyzed and published.

Sulforaphane is an evolved defense mechanism to ward off predators, and eating it is evolutionarily unpleasant. Will people in general and pregnant women in particular eat a diet equivalent to 26% “broccoli sprout seeds?”

Where were peer reviewer comments and researcher responses? Are these not public as they are by all Open Access journals hosted on https://www.mdpi.com/?

Sponsors and researchers become locked into paradigms that permit human-inapplicable animal research year after year. What keeps them from developing sufficient human-applicable evidence to support their hypotheses?


This 2018 Alabama rodent study investigated the epigenetic effects on developing breast cancer of timing a sulforaphane-based broccoli sprouts diet. Timing of the diet was as follows:

  1. Conception through weaning (postnatal day 28), named the Prenatal/maternal BSp (broccoli sprouts) treatment (what the mothers ate starting when they were adults at 12 weeks until their pups were weaned; the pups were never on a broccoli sprouts diet);
  2. Postnatal day 28 through the termination of the experiment, named the Postnatal early-life BSp treatment (what the offspring ate starting at 4 weeks; the mothers were never on a broccoli sprouts diet); and
  3. Postnatal day 56 through the termination of the experiment, named the Postnatal adult BSp treatment (what the offspring ate starting when they were adults at 8 weeks; the mothers were never on a broccoli sprouts diet).

“The experiment was terminated when the mean tumor diameter in the control mice exceeded 1.0 cm.

Our study indicates a prenatal/maternal BSp dietary treatment exhibited maximal preventive effects in inhibiting breast cancer development compared to postnatal early-life and adult BSp treatments in two transgenic mouse models that can develop breast cancer.

Postnatal early-life BSp treatment starting prior to puberty onset showed protective effects in prevention of breast cancer but was not as effective as the prenatal/maternal BSp treatment. However, adulthood-administered BSp diet did not reduce mammary tumorigenesis.

The prenatal/maternal BSp diet may:

  • Primarily influence histone modification processes rather than DNA methylation processes that may contribute to its early breast cancer prevention effects;
  • Exert its transplacental breast cancer chemoprevention effects through enhanced histone acetylation activator markers due to reduced HDAC1 expression and enzymatic activity.

This may be also due to the importance of a dietary intervention window that occurs during a critical oncogenic transition period, which is in early life for these two tested transgenic mouse models. Determination of a critical oncogenic transition period could be complicated in humans, which may partially explain the controversial findings of the adult BSp treatment on breast cancer development in the tested mouse models as compared the previous studies. Thus long-term consumption of BSp diet is recommended to prevent cancers in humans.”

“The dietary concentration for BSp used in the mouse studies was 26% BSp in formulated diet, which is equivalent to 266 g (~4 cups) BSp/per day for human consumption. The concentration of BSp in this diet is physiological available and represents a practical consumption level in the human diet.

Prior to the experiment, we tested the potential influences of this prenatal/maternal BSp regimen on maternal and offspring health as well as mammary gland development in the offspring. Our results showed there was no negative effect of this dietary regimen on the above mentioned factors (data not shown) suggesting this diet is safe to use during pregnancy.”


I didn’t see where the above-labelled “Broccoli Sprout Seeds” diet content was defined. It’s one thing to state:

“SFN as the most abundant and bioactive compound in the BSp diet has been identified as a potent HDAC inhibitor that preferably influences histone acetylation processes.”

and describe how sulforaphane may do this and may do that, and include it in the study’s title. It’s another thing to quantify an animal study into findings that can help humans.

The study’s food manufacturer offers dietary products to the public without quantifying all contents. Good for them if they can stay in business by serving customers who can’t be bothered with scientific evidence.

Any difference between the above-labelled “Broccoli Sprout Seeds” and broccoli seeds? Where was any evidence that “Broccoli Sprout Seeds” and SPROUTED “Broccoli Sprout Seeds” were equivalent per this claim:

“Equivalent to 266 g (~4 cups) BSp/per day for human consumption. The concentration of BSp in this diet is physiological available and represents a practical consumption level in the human diet.”

To help humans, this animal study had to have more details than the food manufacturer provided. These researchers should have either tasked the manufacturer to specify “Broccoli Sprout Seeds” content, or contracted out analysis if they weren’t going to do it themselves.

Regarding timing of a broccoli sprouts diet for humans, this study didn’t provide evidence for recommending:

“Long-term consumption of BSp diet is recommended to prevent cancers in humans.”

http://cancerpreventionresearch.aacrjournals.org/content/early/2018/05/15/1940-6207.CAPR-17-0423.full-text.pdf “Temporal efficacy of a sulforaphane-based broccoli sprout diet in prevention of breast cancer through modulation of epigenetic mechanisms”

Sprouting oats

Three 2020 studies investigated properties of sprouted oats. This first study compared one oat cultivar’s seed and sprout contents for phenolic compounds, and evaluated oat sprouts’ protection against developing colon cancer:

“The purpose of this investigation was to evaluate whether sprouted oats (SO) of the Turquesa variety still possessed effective physiologically bioactive compounds, i.e., phenolics, flavonoids, AVAs [avenanthramides], and phytosterols, and whether it exerted antioxidant and anti-inflammatory effects, as well as the capacity to improve relevant intestinal parameters, in an AOM [azoxymethane] / DSS [dextran sulfate sodium]-induced CRC [colorectal cancer] mouse model.

Suboptimal intake of whole grains (38 g/d) was associated with CRC burden across 16 European countries. An optimal intake of 50–100 g/d was considered in our study to establish the dose administered in the AOM/DSS-induced CRC mouse model (75 g/d).

Seeds (100 g) were soaked in distilled water for 12 h then watered daily. Temperature and relative humidity were set at 25 °C and 60%. Germination was performed in darkness for five days. Germination percentage was determined based on total number of fully emerged seedlings.

We reached 100% of germination and a radicle length of 6.47 ± 0.22 cm. Sprouts were dried at 50 °C for 12 h, milled to a particle size of 0.5 mm, and stored at 4 °C until analyses.

Protein and lipid contents were higher in SO, whereas carbohydrate and ash contents were lower. A more than four-fold increase [0.64 mg/g to 2.79 mg/g] in TPC [total phenolic compounds] was obtained after five days.

We identified AVA-D as the most abundant AVA, followed by AVA-L, which had not been reported as one of the three most abundant AVAs in other oat varieties. Of the three most abundant AVAs previously reported, only AVA-B had a higher abundance in germination.

Phytic acid, an antinutritional compound present in oats, was 10 times lower in oat sprouts. Phytic acid has its content decreased by 15%–35% during even a short three-day germination due to activation of phytase activity. Although high doses of phytic acid inhibit absorption of metals and minerals in humans, it has been observed that, in small doses, it can function as a protective factor in several chronic degenerative diseases.

Mice in groups 3 and 4 were gavaged every morning with phenolic-AVA extract (0.084 mg GAE) and 30 mg of SO, respectively. We observed a mild anti-inflammatory effect of SO and AVA treatments, and a reduced adenocarcinoma incidence of 52.5% and 21.3%, respectively.

SO was more efficient in activating the Keap1-Nrf2 signaling pathway compared to treatment with AVA. Oat phenolic compounds together with β-glucans may be acting synergistically, thus offering greater protection for cancer prevention and treatment.”

https://www.mdpi.com/2304-8158/9/2/169/htm “Chemopreventive Effect of the Germinated Oat and Its Phenolic-AVA Extract in Azoxymethane/Dextran Sulfate Sodium (AOM/DSS) Model of Colon Carcinogenesis in Mice”

The supplementary material developed this oat cultivar’s seed and sprout profiles for 138 phenolic compounds. It measured C-type AVAs, but not A-type AVAs.

This was my model study for Sprouting whole oats.


A second study was reviewed in Eat oats today! and repeated here:

“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.”

https://pubs.acs.org/doi/full/10.1021/acs.jafc.9b06812 “Quantitative Analysis and Anti-inflammatory Activity Evaluation of the A-Type Avenanthramides in Commercial Sprouted Oat Products” (not freely available)

Oat variety and sprout age weren’t available for the six sprouted oat products tested, so oat seed-to-sprout comparisons weren’t possible. A-type AVA comparisons among products were performed, but weren’t meaningful due to unknown varieties, ages, product processing, and storage.


A third study compared four grains’ sprouted and unsprouted contents:

“Seeds were soaked at 25°C in 1 L of distilled water for 20 (brown rice), 12 (sorghum and millet) and 8 h (oat), respectively. Hydrated grains were allowed to germinate with layering over wet cellulose pads in a humid chamber for 60 h at 25°C (oat seeds) or 30°C (brown rice, sorghum, and millet seeds) with 95% relative humidity.

All seeds derived from brown rice and oat were germinated after 48 h in the humid chamber. Germinated grains were dried at 50°C until reaching a moisture content of 10%. Sample seeds were milled to fine flour, screened through a 100-mesh sieve and stored at 4°C for further analysis.

After 60 h of germination, sprout length in sorghum and millet ranged from 8 to 24 mm, while sprouts obtained from brown rice and oat ranged from 3 to 6 mm.

Compared to raw flours, germinated flours derived from brown rice, sorghum, and millet had lower gelatinization enthalpy, whereas germinated oat flour showed higher gelatinization enthalpy.

During germination, enzymes are activated, catalyzing starch degradation, which may disrupt the double helical structure of starch. Consequently, less energy is required to unravel and melt double helices of starch in germinated flours. The increase in gelatinization enthalpy of germinated oat flour may be due to dissolution of hydrolyzed starch granules during germination.”

https://link.springer.com/article/10.1007%2Fs10068-020-00770-2 “Influence of germination on physicochemical properties of flours from brown rice, oat, sorghum, and millet” (not freely available)


The first study sprouted oats for five days to full germination and a minimum radicle length of 6.25 cm. The third study sprouted oats to full germination in 60 hours and a 3 mm minimum total length.

At the same 25°C, with 60% relative humidity and daily watering, it took 120 hours to achieve full germination. With 95% relative humidity, it took half that time.

Was humidity a relevant difference in oat sprout growth? Would Choyang variety oat sprouts increase their minimum 3 mm total length more than 20 times between Hours 60 and 120 to match the minimum Turquesa radicle length?

This is a count of PubMed “oat sprout” search results, 20 results total:

A “broccoli sprout” search returned 648 results. Is oat sprout research just getting started?

Part 2 of The transgenerational impact of Roundup exposure

This 2020 study followed up The transgenerational impact of Roundup exposure using the Washington State Unversity research group’s most recent methodology in DEET and permethrin cause transgenerational diseases:

“The herbicide glyphosate has been shown to promote epigenetic transgenerational inheritance of pathology and disease in subsequent great-grand offspring (F3 generation). The current study was designed to identify epigenetic biomarkers for glyphosate-induced transgenerational diseases using an epigenome-wide association study.

Pathologies investigated included prostate disease [13 of 44 subjects], kidney disease [11 of 44], obesity [19 of 45], and presence of multiple disease [10 of 45]. Sperm were collected from F3 glyphosate lineage males and used to identify specific differential DNA methylation regions (DMRs) and differential histone retention sites (DHRs).

The number of DHRs were less than the number of DMRs, and DHRs were found to have disease specificity. The combination of DMRs and DHRs is anticipated to facilitate pathology diagnosis.

Low sample number is a limitation in the current analysis. Potential higher variability in data needs to be considered.

This is one of the first observations of DHRs as potential biomarkers for disease. The current study used glyphosate induction of transgenerational disease as a proof of concept such environmental biomarkers can be identified and potentially used as diagnostics for disease susceptibility in the future.”

https://www.tandfonline.com/doi/full/10.1080/15592294.2020.1853319 “Epigenome-wide association study for glyphosate induced transgenerational sperm DNA methylation and histone retention epigenetic biomarkers for disease”