Wild primate microbiomes prevent obesity in germ-free mice

The gut microbiome harbors trillions of bacteria that play a major role in dietary nutrient extraction and host metabolism. Metabolic diseases such as obesity and diabetes are correlated with shifts in microbiome composition and have been on the rise in Westernized countries. At the same time, Westernized diets low in dietary fiber have been shown to cause loss of gut microbial diversity. However, the link between microbiome composition, loss of dietary fiber, and obesity has not been shown. To study the interactions between gut microbiota, dietary fiber, and obesity, we transplanted captive and wild primate gut microbiota into germ-free mice and then exposed them to either a high- or low-fiber diet. The group receiving captive primate microbiota gained significantly more weight, regardless of diet, while mice receiving a high-fiber diet and wild primate microbiota remained healthy. In the presence of a low-fiber diet, the wild primate microbiota partially prevented weight gain. Using 16s rRNA gene sequencing we identified key bacterial taxa in each group, specifically a high abundance of Bacteroidetes in captive donor mice and a higher abundance of Firmicutes in the wild-donor mice. These results suggest that wild NHP microbiota could serve as a reservoir for potentially protective therapeutic microbes for cross-species transplants.