From: "Lawrence F. London, Jr." <venaurafarm@bellsouth.net>
To: permaculture <permaculture@lists.ibiblio.org>
Subject: [permaculture] Probiotics may alter gene expression in human digestive tract flora.
Date: Mon, 31 Oct 2011 14:21:34 -0400
http://boingboing.net/2011/10/31/how-yogurt-can-alter-gene-expression.html
How yogurt can alter gene expression
By Maggie Koerth-Baker at 10:49 am Monday, Oct 31
Scientists don't actually know how the bacteria in yogurt and other
fermented foods help humans digest food easier. But a recent study hit
on a possible explanation. Turns out, some probiotics seem to be capable
of altering gene expression in our native gut flora.
Jeffrey Gordon, a microbiologist at Washington University in St. Louis,
and his team gave a commercially-available probiotic yogurt containing
five strains of bacteria to healthy adult volunteers and administered
the same five strains to mice that harbored a subset of
genetically-characterized human gut microbes. The yogurt bacteria did
not significantly alter population structure in any of the entrenched
gut microbes, in humans or mice—a result that is not surprising,
according to Mills. “To assume that you could eat a yogurt and
numerically challenge what’s in your gut is kind of like dumping a
gallon of Kool-Aid in your swimming pool and expecting it to change
color,” he said.
But RNA sequencing of the human gut microbes in the mice revealed that
the probiotic bacteria changed the expression of gut microbe genes
encoding key metabolic enzymes, such as those involved in the catabolism
of sugars called xylooligosaccharides, which are found in many fruits
and vegetables. Mass spectrometry of metabolites in urine, which result
from the ramped up metabolic processes in the probiotic-fed mice,
confirmed the alterations, and when the researchers ran similar analyses
on gut microbes from the human yogurt eaters, they found upregulation of
the same genes.
This study won't be the final word on the subject of how probiotics
work. It needs to be replicated and, even then, there are still a lot of
questions that need answering. But it does represent an interesting peek
inside an interaction between our bodies and other life forms. Cool stuff!
[permaculture] Probiotics may alter gene expression in human digestive tract flora.,
Lawrence F. London, Jr., 10/31/2011