Our genes shape our gut bacteria
Date:
July 8, 2021
Source:
University of Notre Dame
Summary:
Researchers discovered that most bacteria in the gut microbiome
are heritable after looking at more than 16,000 gut microbiome
profiles collected over 14 years from a long-studied population
of baboons in Kenya's Amboseli National Park.
FULL STORY ==========================================================================
Our gut microbiome -- the ever-changing "rainforest" of bacteria living
in our intestines -- is primarily affected by our lifestyle, including
what we eat or the medications we take, most studies show.
==========================================================================
But a University of Notre Dame study has found a much greater genetic
component at play than was once known.
In the study, published recently in Science, researchers discovered
that most bacteria in the gut microbiome are heritable after looking
at more than 16,000 gut microbiome profiles collected over 14 years
from a long-studied population of baboons in Kenya's Amboseli National
Park. However, this heritability changes over time, across seasons and
with age. The team also found that several of the microbiome traits
heritable in baboons are also heritable in humans.
"The environment plays a bigger role in shaping the microbiome than your
genes, but what this study does is move us away from the idea that genes
play very little role in the microbiome to the idea that genes play
a pervasive, if small, role," said Elizabeth Archie, professor in the Department of Biological Sciences and a principal investigator on the
study who is also affiliated with the Eck Institute for Global Health
and the Environmental Change Initiative.
The gut microbiome performs several jobs. In addition to helping with
food digestion, it creates essential vitamins and assists with training
the immune system. This new research is the first to show a definitive connection with heritability.
Previous studies on the gut microbiome in humans showed only 5 to 13
percent of microbes were heritable, but Archie and the research team hypothesized the low number resulted from a "snapshot" approach to
studying the gut microbiome: All prior studies only measured microbiomes
at one point in time.
==========================================================================
In their study, the researchers used fecal samples from 585 wild Amboseli baboons, typically with more than 20 samples per animal. Microbiome
profiles from the samples showed variations in the baboons' diets between
wet and dry seasons. Collected samples included detailed information
about the host, including known descendants, data on environmental
conditions, social behavior, demography and group-level diet at the time
of collection.
The research team found that 97 percent of microbiome traits,
including overall diversity and the abundance of individual microbes,
were significantly heritable. However, the percentage of heritability
appears much lower -- down to only 5 percent -- when samples are tested
from only a single point in time, as is done in humans. This emphasizes
the significance of studying samples from the same host over time.
"This really suggests that in human work, part of the reason researchers haven't found that heritability is because in humans they don't have
a decade and half of fecal samples in the freezer, and they don't have
all the initial host (individual) information they need to tease these
details out," said Archie.
The team did find evidence that environmental factors influence
trait heritability in the gut microbiome. Microbiome heritability was
typically 48 percent higher in the dry season than in the wet, which
may be explained by the baboons' more diverse diet during the rainy
season. Heritability also increased with age, according to the study.
Because the research also showed the significant impact of environment
on the gut microbiomes in baboons, their findings agreed with previous
studies showing that environmental effects on the variation in the gut microbiome play a larger role than additive genetic effects. Combined
with their discovery of the genetic component, the team plans to refine
its understanding of the environmental factors involved.
But knowing that genes in the gut microbiome are heritable opens the door
to identifying microbes in the future that are shaped by genetics. In
the future, therapies could be tailored for people based on the genetic
makeup of their gut microbiome.
The Amboseli Baboon Project, started in 1971, is one of the
longest-running studies of wild primates in the world. Focused on the
savannah baboon, the project is located in the Amboseli ecosystem of
East Africa, north of Mount Kilimanjaro. Research teams have tracked
hundreds of baboons in several social groups over the course of their
entire lives. Researchers currently monitor around 300 animals, but have accumulated life history information on more than 1,500 animals.
The research was funded by the National Science Foundation.
========================================================================== Story Source: Materials provided by University_of_Notre_Dame. Original
written by Deanna Csomo McCool. Note: Content may be edited for style
and length.
========================================================================== Journal Reference:
1. Laura Grieneisen, Mauna Dasari, Trevor J. Gould, Johannes R. Bjo"rk,
Jean-Christophe Grenier, Vania Yotova, David Jansen, Neil Gottel,
Jacob B. Gordon, Niki H. Learn, Laurence R. Gesquiere, Tim L. Wango,
Raphael S.
Mututua, J. Kinyua Warutere, Long'ida Siodi, Jack A. Gilbert,
Luis B.
Barreiro, Susan C. Alberts, Jenny Tung, Elizabeth A. Archie,
Ran Blekhman. Gut microbiome heritability is nearly
universal but environmentally contingent. Science, 2021 DOI:
10.1126/science.aba5483 ==========================================================================
Link to news story:
https://www.sciencedaily.com/releases/2021/07/210708170331.htm
--- up 8 weeks, 6 days, 22 hours, 45 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)