The microbes that inhabit our digestive tract, skin, mouth, and other body parts--known collectively as the human microbiome--play a key role in human health, influencing metabolism, immune function, and more. (Each of us contains roughly 10 times as many microbial cells as human ones.) Scientists are exploring a number of ways to manipulate one's microbes, including eating foods such as yogurt that contain healthy bacteria. But transplanting entire microbial populations may provide a more powerful way to overhaul our intestinal ecosystems. Eating more yogurt, for instance, hasn't helped people with C. difficile infections, says Rob Knight, associate professor of chemistry and biochemistry at the University of Colorado at Boulder.
Knight and collaborators from Barcelona, Spain, are studying microbe transplants in rodents with the hope of more effectively applying the approach to people. In a paper published last week in the journal Genome Research, the researchers demonstrated that they could successfully transplant the entire microbial community of one healthy rat's digestive system into another's. After three months, the recipient's microbiome more closely resembled the donor's, though the two microbiomes were not identical.
They also reported that Antibiotics , which they had hoped would make the colonization easier, actually impeded growth. Animals treated with the drugs prior to the transplant ended up with a less diverse microbiome, which also had less resemblance to the donor's. Though the finding needs to be confirmed in people, it suggests that Antibiotics might be counterproductive in the transplantation process, says Knight.