Ancient Gut Bacteria Shared by Distant Foraging Groups Are Missing in Industrialized People
A Stanford study published in Nature compared gut microbiomes from Tanzania’s Hadza hunter-gatherers and Bolivia’s Tsimane forager-horticulturalists. The two groups, separated by continents and different diets, shared 1,231 bacterial species, with roughly 60% of those species rare or missing in industrialized populations. The researchers propose that many of these microbes traveled with human ancestors for tens of thousands of years before being lost in modern industrialized guts.
The Stanford team compared gut microbes from Tanzania’s Hadza, who forage for wild foods, and Bolivia’s Tsimane, who farm and eat fiber-rich crops. They found 1,231 shared bacterial species; roughly 60% are scarce or absent in industrialized people. The Tsimane sample contained about 1,400 species, nearly 90% of which also appeared in the Hadza.
Bacterial DNA analysis suggested some shared lineages diverged around major human migrations, including out of Africa and into the Americas. Industrialized microbiomes tend to be less diverse, possibly due to antibiotics, processed foods, and sanitized settings. Reduced microbial diversity has been linked to obesity, Type 2 diabetes, and autoimmune conditions, though direct causation remains unclear.
This research may influence how scientists, clinicians, and the public view industrialized gut microbiomes. If ancient microbes matter for health, people in industrialized settings could be most affected by their absence, while forager and farming communities might help identify what has been lost. Probiotic, dietary, or microbiome-based interventions could eventually be explored, but causality is unresolved. The findings may also shape debates about urbanization, sanitation, and diet, though they do not yet justify specific medical or policy recommendations.