Study Finds Gut Microbes Traced Human Migration Across Continents

A new study published in the journal Nature indicates that the gut microbiomes of humans have traveled alongside their hosts across continents for thousands of years. Researchers examined the bacterial profiles of two distinct rural communities: the Hadza, who are hunter-gatherers in northern Tanzania, and the Tsimane, who forage and fish in the Bolivian Amazon. Despite being separated by approximately 7,000 miles and having different subsistence strategies, the two groups exhibit remarkable similarities in their gut bacteria.

The findings suggest that this microbial kinship originated long before human migration patterns separated the ancestors of these populations. The research, which analyzed stool samples from both groups, also highlighted a significant divergence between these rural communities and urban populations, even those living in close proximity to the study sites.

Justin Sonnenburg, a professor of microbiology and immunology at Stanford University and the senior author of the study, emphasized the long-standing relationship between humans and these bacteria. “If we were inhabited by very similar microbes over a long period of time, it suggests that our human genomes may have come to expect a certain set of microbes and functions,” Sonnenburg said. He noted that the loss of microbial biodiversity due to modern lifestyles could pose serious challenges for human biology.

The study underscores the potential health implications of losing ancient microbial strains, raising questions about how contemporary living affects the delicate balance between human genomes and the bacteria that coexist with them.