When Jessica Green competed in roller derby, she wondered how training, socializing and colliding with other roller girls could be affecting her health in invisible ways.
As a member of the Emerald City Roller Girls, Green went by "Thumper Biscuit" on the track, but she is also the director of the Biology and the Built Environment Center at the University of Oregon. She and her colleagues just published a study in the journal PeerJ looking at the bacteria that live on the skin of roller derby team members and how they're swapped around during competition.
According to the official rules of the Women's Flat Track Derby Association, players are allowed to make contact at the arms, chest, hips and thighs when jockeying for track position. (If you've ever seen roller derby you know that "contact" is a pretty mild word for what goes on.)
Researchers swabbed the exposed upper arms of roller derby players on three teams from different cities before and after "bouts" at a tournament in Emerald City's home base of Eugene, Ore. They found that before a bout, the different teams had distinct populations of skin microbes.
"We could have picked out one player at random, and just by looking at the bacteria on her upper arm, we could have told you what team she played for," says James Meadow, a postdoctoral researcher at the BioBE Center who led the study.