Chimpanzees share with humans a tendency to recruit particular communities of bacteria in the gut, according to new work published this week in Nature Communications. The findings suggest that the factors influencing which bacteria are able to colonize our intestines have more ancient evolutionary origins than was originally predicted.
Humans can generally be categorized into one of several groups known as enterotypes based on characteristic patterns of bacterial species present in the gut. Individuals can switch enterotype over periods of years, and enterotype selection is thought to be influenced by diet. Howard Ochman and his team show that chimpanzees can also be grouped into enterotypes that strikingly resemble those found in humans. The authors infer from these findings that these different groups are therefore unlikely to have emerged during evolution as a direct response to the diversity of the human diet. Instead they suggest that the enterotypes are probably determined by aspects of our biology, such as our immune system, which we share with other primates.