Our genes shape our gut bacteria, new research shows
In the study, published recently in Science, researchers found that most bacteria in the gut microbiome are inherited after examining more than 16,000 gut microbiome profiles collected over 14 years from a population of baboons long studied in the world. Amboseli National Park in Kenya.
University of Notre-Dame
Our gut microbiome – the ever-changing “rainforest” of bacteria living in our gut – is primarily affected by our lifestyle, including what we eat or the drugs we take, as most studies show.
But a university of Notre Dame study found a much larger genetic component than previously known.
In the study recently published in Science, researchers found that most bacteria in the gut microbiome are inherited after examining more than 16,000 gut microbiome profiles collected over 14 years from a long-studied baboon population in Amboseli National Park in Kenya. However, this heritability changes over time, with the seasons and with age. The team 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, but this study takes us away from the idea that genes play very little role in the microbiome to the idea that genes play a ubiquitous role, even though it’s small, “said Elizabeth Archie, professor in the Department of Biological Sciences and lead researcher on the study, also affiliated with the Eck Institute for Global Health and the Environmental Change Initiative.
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. This new research is the first to show a definitive link with heritability.
Previous studies of the gut microbiome in humans have shown that only five to 13% of microbes are inherited, but Archie and the research team hypothesized that the low number was the result of an “instant” approach to study the gut microbiome: All previous 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. The microbiome profiles of the samples showed variations in the diet of baboons between wet and dry seasons. Samples collected included detailed information about the host, including known offspring, data on environmental conditions, social behavior, demographics, and diet at the group level at the time of collection.
The research team found that 97 percent of the traits of 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 five percent – 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, ”Archie said.
The team found evidence that environmental factors influence the heritability of traits in the gut microbiome. 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 increased with age, according to the study.
Because research has also shown the significant impact of the environment on the gut microbiome of baboons, their results are consistent with previous studies showing that environmental effects on gut microbiome variation play a larger role than additive genetic effects. . Together with their discovery of the genetic component, the team plans to refine their understanding of the environmental factors involved.
But knowing that genes in the gut microbiome are hereditary opens the door to future identification of genetically shaped microbes. In the future, therapies may be tailored for people based on the genetic makeup of their gut microbiome.
The Amboseli Baboon project, launched in 1971, is one of the oldest studies of wild primates in the world. Centered on the savannah baboon, the project is located in the Amboseli ecosystem in East Africa, north of Mount Kilimanjaro. Research teams have followed hundreds of baboons in several social groups over the course of their lifetimes. Researchers currently monitor around 300 animals, but have accumulated information on the life cycle of more than 1,500 animals.
– This press release was originally published on the Notre-Dame University website