Researchers have found an intermediate gut microbiome in a community of a traditional population that incorporates some westernised lifestyle practices and throws light on why modern humans suffer from lifestyle diseases.

“This is one of the first studies to show that the microbiomes of a traditional agriculturalist group exhibit an intermediate state, between the microbiomes of hunter-gatherers and those of a western industrialised society,”said Andres Gomez, microbial ecologist at the J Craig Venter Institute in California.

In the study, the team described an intermediate gut microbiome from the Central African Republic’s Bantu community.

The discovery offers insight into what factors may drive our microbiome differences which are thought to be linked to metabolic disorders in western populations.

“The study supports the idea that diet is the most important driver of microbiome composition in humans. We are what we eat, and our microbiome is a very important reflection of lifestyle,” Gomez added in a paper published in the journal Cell Reports.

According to him, the Bantu traditional agriculturalists have been gradually transitioning to westernised subsistence patterns, and this transition may have been the way modern humans evolved their gut microbiomes.

The hunter-gatherers (called BaAka) analysed in the study rely heavily on wild game, fish and fruits and vegetables for sustenance.

However, the Bantu population relies fully on a market economy.

These agriculturalists grow tubers, fruits and other plants, make use of flour-like products, and raise goats for meat.

They also use antibiotics and other therapeutic drugs when available.

Sequencing data revealed that while the BaAka and Bantu gut microbes were from similar bacterial species, the abundance of traditional bacterial groups was diminished in the Bantu.

Further comparisons with western microbiome data showed that the Bantu microbiome composition falls on a spectrum between the BaAka and western populations.

“The BaAka microbiome is more similar to that of wild primates than it is to western humans,” Gomez noted.

The study involved a team of international collaborators, including senior author Ran Blekhman of the University of Minnesota.