permaculture

[Lawrence London <lfljvenaura@gmail.com>]

A comment:

I'm not sure why the discussion of the microbiome always focuses on fiber
as amino acids are fermented by bacteria and produce benificial SCFA

https://www.sciencedirect.com/science/article/pii/S1075996497901219

Abstract

The abilities of slurries of human faecal bacteria to ferment 20 different
amino acids were investigated in batch culture incubations. Ammonia, short
chain fatty acids, and in some cases, amines, were the principal products
of dissimilatory metabolism. The types of SCFA produced were dependent on
the chemical compositions of the test substrates. Thus, acetate and
butyrate were formed from the acidic amino acid glutamate, while acetate
and propionate predominated in aspartate fermentations. Breakdown of the
basic amino acids lysine and arginine was rapid, and yielded butyrate and
acetate, and ornithine and citrulline, respectively. The major products of
histidine deamination were also acetate and butyrate. However, fermentation
of sulphur-containing amino acids was slow and incomplete. Acetate,
propionate and butyrate were formed from cysteine, whereas the main
products of methionine metabolism were propionate and butyrate. The simple
aliphatic amino acids alanine and glycine were fermented to acetate,
propionate and butyrate, and acetate and methylamine, respectively.
Branched-chain amino acids were slowly fermented by colonic bacteria, with
the main acidic products being branched-chain fatty acids one carbon atom
shorter than the parent amino acid. Low concentrations of amines were also
detected in these fermentations. Aliphatic-hydroxy amino acids were rapidly
deaminated by large intestinal microorganisms. Serine was primarily
fermented to acetate and butyrate, while threonine was mainly metabolised
to propionate. Proline was poorly utilized by intestinal bacteria, but
hydroxyproline was efficiently fermented to acetate and propionate. The
aromatic amino acids tyrosine, phenylalanine and tryptophan were broken
down to a range of phenolic and indolic compounds.

Interestingly the by product of microbial breakdown of most of the AA was
SCFA, which are suspected to be very beneficial to gut health among other
things.

https://www.frontiersin.org/articles/10.3389/fmicb.2016.00185/full

On Fri, Feb 22, 2019 at 6:18 PM Lawrence London <lfljvenaura@gmail.com>
wrote:

> Beans may be the very best thing you can eat for your microbiome. Here is
> why. : nutrition
>
> https://www.reddit.com/r/nutrition/comments/athyam/beans_may_be_the_very_best_thing_you_can_eat_for/?st=jsgo80ul&sh=9b52c3ee
>
> "First off beans are the cornerstone for every blue zone diet in the world
>
> https://www.bluezones.com/2016/06/10-things-about-beans/
>
> So there's that. But for the microbiome they are incredible. First
> understand how important Resistant starch is for the microbiome.
>
>
> https://www.dermveda.com/articles/why-you-should-eat-resistant-starch-for-a-healthy-microbiome
>
> Resistant starch is metabolized by microbes in the gut to produce
> molecules called short chain fatty acids, such as acetate, butyrate and
> propionate. These short chain fatty acids have significant health benefits,
> including cancer fighting benefits and anti-inflammatory effects.[4,5]
> Diets high in resistant starch lead to higher levels of short chain fatty
> acids and may offer protection against colon inflammation and disease.[6]
> The dietary fiber that is fermented by our gut microorganisms are referred
> to as “prebiotics,” leading to the production of beneficial short chain
> fatty acids and other molecules, including serotonin and deoxycholic
> acid.[7,8]
>
> Eating resistant starch may even improve problems with insulin regulation,
> including insulin resistance and diabetes.[9]
>
>
> https://www.gutmicrobiotaforhealth.com/en/new-review-explores-latest-knowledge-resistant-starch-nutrition-modulator-gut-microbiota/
>
> In addition, RS (resistant starch) has specific beneficial effects on the
> gut environment including increased populations of Ruminococcus bromii -a
> dominant member of the phylum Firmicutes that plays a primary role in
> releasing energy from dietary starches that escape digestion by host
> enzymes through its exceptional activity against particulate resistant
> starches. Besides this, ingestion of food products rich in RS has been
> shown to increase luminal short-chain fatty acid levels, modulate microbial
> metabolism and improve markers of glucose homeostasis and insulin
> sensitivity
>
> Regarding cell signalling pathways that can explain physiological effects
> of RS, using animal models it has been well documented that *resistant
> starch has strong anti-inflammatory properties*
>
> And beans are far and away the best source of resistant starch in our
> diets. They have many more times the RS as any other commonly eaten food.
> See here for more.
>
>
> https://www.hsph.harvard.edu/nutritionsource/2015/11/16/ask-the-expert-legumes-and-resistant-starch/
>
> Eating beans may even alter the microbiome in such a way as to kill cancer
> cells!
>
>
> https://www.healio.com/gastroenterology/oncology/news/online/%7B1d9afc8b-cef1-4b45-94bc-61dbfc08144b%7D/rice-bran-navy-beans-boost-gut-microbiome-slow-crc-cell-growth
>
> To evaluate the chemopreventive effects of rice bran and navy bean intake,
> Ryan and colleagues performed a phase 2 pilot study (the BENEFIT trial), in
> which they randomly assigned 29 CRC survivors to consume 30 grams of rice
> bran per day, 35 grams of navy bean powder per day, or neither for 4 weeks.
>
> They found that increased consumption of rice bran and navy beans led to
> higher dietary levels of fiber, iron, zinc, thiamin, niacin, vitamin B6,
> folate, and alpha-tocopherol. Further, stool microbiome analyses revealed
> the rice bran group had increased gut microbial richness and diversity, and
> the navy bean group showed increased gut microbial richness.
>
> Notably, analysis of human stool metabolite extracts before and after the
> dietary intervention showed increased intake of rice bran or navy beans
> reduced growth of colorectal cancer cells.
>
> There's more but thats all I will post for now."
>


-- 
Lawrence F. London, Jr.
lfljvenaura@gmail.com
https://sites.google.com/site/avantgeared