“Moeller found that two of three major families of gut bacteria in apes and humans trace their origins to a common ancestor more than 15 million years ago”
Andrew H. Moeller, Alejandro Caro-Quintero, Deus Mjungu, Alexander V. Georgiev, Elizabeth V. Lonsdorf, Martin N. Muller, Anne E. Pusey, Martine Peeters, Beatrice H. Hahn, Howard Ochman. Cospeciation of gut microbiota with hominids. Science, 2016 DOI: 10.1126/science.aaf3951