In the News, Summer 2017: Hunter-Gatherers Provide Insight into Gut Microbiome

A study published in the journal Science provides new evidence that our intestinal microbiomes are greatly influenced by what we eat. The researchers examined the gut-microbial composition of a group of Hazda hunter-gatherers residing in the Rift Valley of Tanzania. They found not only that the Hadza microbiota is significantly different – and more diverse – than that of people following typical Western diets, but also that seasonal variations in the hunter-gatherers’ diet are linked to cyclical changes in microbial composition.

Fewer than 200 Hazda still adhere to their traditional diet, based largely on meat, berries, baobab fruit, tubers, and honey. The relative availability of these foods varies between the wet and dry seasons. An analysis of stool samples revealed that the Hazda’s gut bacteria fluctuate accordingly; for example, some species diminish in the wet season, when honey makes up a major part of caloric intake, and increase in the dry season, when there is greater consumption of tubers.

Senior author Justin Sonnenburg, PhD, observes: “Surviving hunter-gatherer populations are the closest available proxy to a time machine we in the modern industrialized world can climb into to learn about the ways of our remote human ancestors.” The findings suggest that dietary changes in the past 10,000 years have played a key role in the loss of gut-microbial diversity among Westernized people.

SOURCE: Hunter-gatherers of Tanzania experience seasonal variation in gut-microbe diversity. Stanford Medicine, August 24, 2017. http://med.stanford.edu/news/all-news/2017/08/hunter-gatherers-seasonal-gut-microbe-diversity-loss.html.