A recent discovery has revealed that the human gut microbiome, regarded as the dynamic ‘rainforest’ of bacteria in our intestines, is actually impacted by our genes, not the ways humans live, eat and medicate as the previous studies indicated.

A group of researchers from the University of Notre Dame found that the majority of the bacteria present in the gut microbiome are heritable after studying over 16,000 gut microbiome profiles gathered over 14 years from baboons belonging to Kenya’s Amboseli National Park.

Nevertheless, this heritability varies across time, seasons, and age. The research members also discovered that numerous microbiome traits which are heritable in baboons are similarly heritable in humans.

Past studies on the gut microbiome in humans have shown that 5 to 13 percent of microbes are heritable, but the research members built a hypothesis that the low number emerged from a ‘snapshot’ technique to examining the gut microbiome, as all former studies measured microbiomes at a singular point in time. This latest research is the first to present a definite relationship with heritability.

Gut microbiome helps in food digestion, producing essential vitamins and helps training the immune system.

How did the researchers find out?, the researchers utilized fecal samples from 585 wild Amboseli baboons, taking above 20 samples per animal. These samples of microbiome profiles displayed alterations in the baboons’ diets within wet and dry seasons.

The samples also revealed information regarding the host, recognised descendants, environmental condition, demography, social behaviour, and the diet at the moment of collection.

The Amboseli Baboon Project initiated in 1971, is administering studies of wild primates for a long time. The project is focused on the savannah baboon and is located in the Amboseli ecosystem of East Africa, north of Mount Kilimanjaro. The researchers currently observe about 300 animals yet have gained life history knowledge on more than 1,500 animals.

The research uncovered that 97 percent of microbiome traits are significantly heritable such as the total diversity and the high number of individual microbes. Moreover, the percentage of heritability seems to be low, dropping to simply 5 percent, when samples are experimented with at a single point in time, as tested in humans. This highlights the importance of studying samples from the same host over a long period.

There was also an evidence that environmental factors impact trait heritability in the gut microbiome. In the dry season, the microbiome heritability was 48 percent higher than in the wet due to the diverse diet of baboons in the rainy seasons.

According to the research, heritability also increased with age.The findings of the environmental factors impacting heritability were in agreement with the prior studies, thus the research confirms that variation in the gut microbiome performs a larger role than genetic influences. The team now plans to further research on the microbiome gut, including the discovering of genetic involvement.

The discovery that genes in the gut microbiome are heritable unlocks the key to recognizing microbes that are formed by genetics. Also, treatments could be formulated for humans by studying the genetic composition of their gut microbiome.