Most Bacteria In Gut Microbiome Are Hereditary, New Study Finds | Biology, Genetics
Commensal bacteria are found throughout an organism, but it is not known whether the associations between gut bacteria and their host are hereditary. In a new study, biologists from the University of Notre Dame and elsewhere examined changes in the microbiomes of 585 wild baboons from samples collected over 14 years in Amboseli National Park in Kenya; almost all of the microbiome traits tested demonstrated some statistically significant level of heritability; the researchers also found that many of the inherited microbiome traits in baboons are also inherited in humans.
“The environment plays a more important role in the formation of the microbiome than your genes,” said Professor Elizabeth Archie, a researcher in the Department of Biological Sciences at the University of Notre Dame.
“But what our study does is move us away from the idea that genes play very little role in the microbiome to the idea that genes play an ubiquitous role, however small it is.”
The gut microbiome performs several functions. In addition to aiding in the digestion of food, it creates essential vitamins and helps in the formation of the immune system.
Previous studies of the gut microbiome in humans have shown that only 5-13% of microbes are hereditary, but Prof Archie and colleagues hypothesized that the low number was the result of an ‘instant’ approach to studying gut microbiome: All previous studies only measured microbiomes at one point in time. on time.
In their study, the researchers examined 16,234 gut microbiome profiles of 585 wild Amboseli baboons.
The microbiome profiles of the samples showed variations in the diet of baboons between wet and dry seasons.
Scientists found that 97% of traits in the microbiome, including the overall diversity and abundance of individual microbes, were significantly hereditary.
However, the percentage of heritability appears to be much lower – down to just 5% – when samples are tested from a single point in time, as is the case in humans. This highlights the importance of studying samples from the same host over time.
“This really suggests that in human labor, part of the reason researchers haven’t found heritability is because in humans they don’t have a decade and a half of fecal samples in the freezer. , and they don’t have all the initial host (individual) information they need to reveal those details, ”Professor Archie said.
The heritability of the microbiome was generally 48% higher during the dry season than during the wet season, which can be explained by the more diverse diet of baboons during the rainy season. Heritability also increases with age.
“Because the study also showed the significant impact of the environment on baboon gut microbiomes, our results are consistent with previous studies showing that environmental effects on gut microbiome variation play a more important role than effects. genetic additives, ”the authors said.
Their findings appear this week in the newspaper Science.
Laura Grieneisen et al. 2021. The heritability of the gut microbiome is almost universal but depends on the environment. Science 373 (6551): 181-186; doi: 10.1126 / science.aba5483