Scientists are studying samples of bacteria to see why successful athletes' microbiomes differ from those of non-athletes.

Another kind of superbug: Seeking an edge in the elite athlete’s microbiome

Two years ago, Jonathan Scheiman grabbed a Zipcar and, for lack of a better term, turned it into a traveling pooper-scooper.

He cruised through Boston and Cambridge every day, picking up fecal samples from runners training for the Boston Marathon and storing them on dry ice. His aim: seeing if the bounties of bacteria found in the samples contained any secrets to the runners’ athletic success, and determining whether it would be possible to resettle such bacteria into the bodies of others.