Gut microbes followed migrating humans across continents, new study suggests

A Tsimane extended family gets ready for the morning, while a large pot of manioc roots cooks in preparation to make shocdye, a local fermented brew. Michael Gurven hide caption Michael Gurven The Hadza people are hunter-gatherers who have roamed northern Tanzania for thousands of years. The indigenous Tsimane people forage, fish and hunt in the Bolivian Amazon, some 7,000 miles away. These two rural communities, separated by an ocean, may appear to have little in common. But a new study shows that they share remarkable similarities when it comes to the bacteria in their guts. For stories of life in our changing world, subscribe here to the global health newsletter. Experts say the new paper in the journal Nature suggests this microbial kinship may have taken shape long ago, before human migration split these groups' ancestors apart. The study, which relied on stool samples from both groups, also showed that both the Hadza and Tsimane microbiomes were markedly different from city folk, even those living nearby. The findings suggest that some strains of gut bacteria have long coexisted with humans, possibly to their mutual benefit. It's an idea that some scientists say raises questi...