Nature Study Finds Hadza and Tsimane Share Gut Microbes, but Industrialized Populations Have Lost Many Strains

A study published in Nature on October 7 has found that the Hadza people from Tanzania and the Tsimane from the Amazon have over 1,200 gut microbial species in common, even though they live on different continents. Almost 90 percent of the microbial species present in the Tsimane were also found in the Hadza. Interestingly, about 60 percent of these strains are either rare or completely absent in urban populations. Co-authored by Stanford microbiologist Justin Sonnenburg, the research suggests industrialization has led to a significant decline in the diversity of ancestral gut microbiomes. Sonnenburg's earlier work in 2023 showed that Californians have an average of just 277 microbial species, while Hadza individuals have around 730. The two groups are believed to have diverged from a common ancestor roughly 17,000 years ago. While this study doesn’t establish that ancient microbiomes are better, it raises questions about the implications of losing ancestral microbes. Andrew Moeller from Princeton notes the effects of this loss are still unclear, and Marie-Claire Arrieta from the University of Calgary stresses the importance of studying these lost functions, even if reverting to ancient microbiomes isn’t realistic.