Chimpanzees and humans have similar gut microbes

The human gut hosts numerous species of microbes (the microbiome) — so many that in our bodies, microbe cells outnumber human cells ten to one. Many of these microbes appear to be important for digesting our food and maintaining health, while others have been implicated in disease, such as Crohn’s disease and irritable bowel syndrome. Recent studies have found that human microbiomes can be broadly classified into three enterotypes based on the relative abundance of different microbe species. This finding raised the question: are these enterotypes the product of a long history of co-evolution between microbes and humans, or are they a recent product of changes in diet, such as those resulting from agriculture and processed foods?

Frodo feeding in an oil palm tree.

I played a small role in a recent study led by Howard Ochman that looked at this question. Ochman’s team examined chimpanzee fecal samples collected at Gombe as part of the ongoing study of SIVcpz led by Beatrice Hahn. By comparing the microbiomes of humans and chimpanzees, Ochman’s team found that the microbiomes of wild chimpanzees can be classified into similar enterotypes to those in humans. This suggests that these patterns of microbiome communities are evolutionarily ancient, predating the common ancestor of humans and chimpanzees (some 5 to 7 million years ago).