Rural and urban microbiota differ from a young age, finds new study

By Sally Robertson, B.Sc.Jun 7 2018

A new study has shown that differences in the human gut microbiome between people living in rural versus urban areas of Nigeria begin at a very young age.

Image Credit: Alexey Godzenko / Shutterstock

The finding, which has recently been published in the journal Cell Reports, could help researchers understand why traditional populations tend to have much lower rates of Western diseases.

Previous studies analyzing the microbiomes have generally compared rural, hunter-gatherer communities with distant urban populations in Europe or the U.S., but this study has compared the microbiomes of rural and urban African people in the same geographical area.

This research was specifically designed to fill in gaps of knowledge about the variation of the human gut microbiome, as well as the metabolome, in relation to subsistence patterns in geographically close populations."

Funmilola Ayeni, First Author

The study was unique because it analysed the microbiomes of both infants (defined as children aged up to three) and adults.

The investigators were surprised to find that infants living in rural areas had microbiome profiles that were generally more diverse and more similar to those of adults.

The diet of people living in rural areas consisted of tubers, grains, leafy soups and untreated water, whereas the diet of those living in urban areas included processed foods and treated water, but had more elements of a traditional Nigerian diet than in Western countries.

Ayeni and team found that the intestinal microbiota of rural people contained more of the bacterial species that are needed to digest fiber. They also had lower levels of amino acids and biogenic amines, suggesting that they consumed less protein.

We've always assumed that the microbiomes of infants were the same everywhere, and that differences came later in life. We were surprised to find that the microbiomes of infants living in rural areas were missing components that we have long believed were standard to all infant populations.”

Silvia Turroni, Senior Author

Turroni says the findings are notable and that studies like this have profound evolutionary relevance because they recall ways of life that have characterized human history, from the hunting and gathering of our Paleolithic ancestors to small-scale agriculture, to the post-industrial Western lifestyle.

The distinctive microbial and metabolic traits observed in traditional populations, which tend to have much lower rates of Western diseases, could help researchers understand the mechanisms that lead to the rupture of these microbiome-host relationships.

"This could also potentially result in a greater understanding of the inflammation and immune dysregulation that follows."