On the Serengeti plain, gut bacteria reveal who’s been eating grass and who’s been sampling the gazelle.
What a mammal eats seems to determine the microbial species that live in its intestines and what jobs those microbes take on, an international team of researchers reports May 20 in Science. The nutrients inside meat and veggies predictably influence the different communities of friendly bacteria that inhabit both vegetarian and meat-eating species, the group says.
“This kind of work is foundational,” says Martin Blaser, a microbiologist at New York University who was not involved in this study. “It helps to define the macro rules that govern these things.”
In the study, researchers picked microbes from the feces of 33 mammal species and took a close look at the genes those bugs carried. Of 1,500 pieces of genes that seemed to code for enzymes, 495 were associated with microbes belonging to either herbivores, like the hapless gazelle, or carnivores, such as the lion. Herbivore and carnivore microbes may be different, but they also seem to have different jobs that are determined by diet, says coauthor Jeffrey Gordon, a systems biologist at Washington University in St. Louis.