Human skin is teeming with microbes—communities of bacteria, many of which are harmless, live alongside the more infamous microbes sometimes found on the skin. Nina Rountree from North Carolina State University and colleagues set out to dispel the myth that all bacteria on the skin are disease-causing germs. The researchers cultured the bacterial communities living within bellybuttons of 391 individuals from across the U.S. and published photos of the cultures anonymously in the online Bellybutton Bacteria Culture database. They chose bellybuttons as an area of the body that is generally protected from excretions, soaps and ultraviolet ray exposure.
The experiment generated interest among citizen scientists and provided clues about the stability of bacterial communities over time, the significant turnover between participants' bacterial communities and similarities of bacterial communities between family members. The Bellybutton Bacteria Culture database received 55,000 visitors in only three months.
The authors of the study note that most bacteria found on the skin is actually very harmless. This actually stands to reason. They're so common that if they made us sick, we'd all be chronically ill or dead.
Of course we don't think of bacteria as having communities, as a general rule. Much less do we think of those communities as being on us. Which suggests just how much we filter out in order to go about our business.