Nature: gut microbes shared by Bolivia's Tsimane and Tanzania's Hadza point to prehistoric co-migration with humans

7 October 2026

A Nature paper published on 7 October 2026 compared gut microbiomes of the Tsimane of Bolivia and the Hadza of Tanzania.
The two populations share 1,231 microbial species, most of which are rare in or absent from industrialised populations.
Analysis of 636 shared species shows divergence and gene flow patterns consistent with prehistoric co-migration with humans.
About 60 per cent (848) of shared species are rare in or absent from industrialised populations; the estimated median split time is about 17,090 years.
The corresponding authors are Benjamin H. Good and Justin L. Sonnenburg; Sonnenburg is at Stanford University School of Medicine.