What you eat feeds not only what you think of as you, but also the millions upon millions
of bacteria, yeasts and other microorganisms that are in you—effectively, part
of you.
And increasingly researchers are finding that that mixture
of gut bacteria and other stuff plays a massive role in what makes you you. This is a new frontier in
nutritional and disease science.
Let’s talk a little about how big a deal is this association
between us and our biological tenants.
“All organisms, including humans, exist within a sea of
microorganisms. A select few microbes cause great harm, but most are benign,
some essential,” wrote Caroline Ash and Kristen Mueller in an April 2016
article in the journal Science.
“The human microbiome is a source of genetic diversity, a
modifier of disease, an essential component of immunity, and a functional
entity that influences metabolism and modulates drug interactions,” wrote the
authors Elizabeth Grice and Julia Segre in this paper.
The University of Hawai`i at Manoa is active in the microbiome work.
Canadian researchers have found that babies with particular microscopic
organisms in their systems in the first three months of life are more likely to
have asthma later in life. They studied babies in Canada and babies in Ecuador
and found the same pattern, although it was bacteria in Canadian kids and
yeasts in Ecuadorian kids.
A study in the journal Cell found that kids fed the same
diets could be healthy or malnourished depending on what bacteria they had in
their guts.
A study in the journal Research in Microbiology found that
babies born by caesarian section end up with very different gut biota from
those born vaginally—often with bacteria picked up in the hospital rather than
those from their mothers.
There’s a whole industry, probiotics, that argues that by
eating certain things, you can adjust your microbiome to favor microorganisms
that keep you healthy and disfavor those that make you sick. But there are cautions.
“The probiotic industry currently faces huge challenges.
These range from exaggerated health claims to the difficulties of developing
rigorous testing protocols within existing regulatory frameworks. All the same,
probiotic development shows great promise for rebuilding microbiotas and
restoring health, certainly for some individuals,” wrote Ash and Mueller in
Science.
Earlier this month, the University of Hawai`i hosted the
author of the book, “Let Them Eat Dirt:
Saving Your Child from an Oversanitized World.” In it,
Michael Finlay, with co-author Marie-Clair Arrieta, argue that early exposure
to a range of microscopic life can be beneficial.
A lot of folks eat yogurt for its effect on gut bacteria.
And University of Hawai`i researchers have studied the effects of poi as a
non-dairy player in changing the mix of your internal biology. They didn’t find
much impact from fresh poi, but they suggested that sour poi might have a
different impact.
That paper includes a detailed review of probiotics, and it’s
interesting reading. The authors are Amy C. Brown and Anne Shovic, of the Department
of Human Nutrition, Food and Animal Sciences at the University of Hawaii at
Manoa, Salam Ibrahim, of the Food Microbiology and Biotechnology Laboratory,
Department of Human Environment and Family Sciences, North Carolina A&T
State University, Peter Holck, of the John A. Burns School of Medicine, and
Alvin Huang, of the Department of Human Nutrition, Food and Animal Sciences,
University of Hawaii at Manoa. Their paper is here.
They wrote, in part, that “The probiotic theory is supported
by the fact that a disruption in the intestine’s delicate balance may
contribute to diarrhea, gastroenteritis, constipation, irritable bowel
syndrome, inflammatory bowel disease (Crohn’s disease and ulcerative colitis), food
allergies, and certain cancers. On the contrary, a balanced or “normal” enteric
flora may competitively exclude possible pathogenic organisms and stimulate the
intestinal immune system.”
So what all is in there? “The human microbiome is composed
of bacteria, archaea, viruses and eukaryotic microbes that reside in and on our
bodies. These microbes have tremendous potential to impact our physiology, both
in health and in disease,” wrote the authors of this paper.
Clearly, we’re learning a lot, but there are vast amounts
left to learn. Hawai`i will be part of the information gathering, in part
through the university’s involvement in the National Microbiome Initiative.
© Jan TenBruggencate 2017