Your belly button is a veritable biosphere, housing an average of 67 different species of bacteria, according to a new study that examined the contents of people's navels. Researchers found that our belly buttons are filled with living organisms "that we don't know much about."
For the study—which was published in the journal PLoS ONE—66 men and women swabbed their navels with sterile Q-Tips, from which researchers then cultured bacteria. In all, they found 2,368 different species of bacteria, which is a lot of "biological diversity" for the amount of people involved in the study. (The colonies of bacteria were photographed and are viewable online.)
The most common were Staphylococci, which helps your skin defend itself from bad germs; Micrococcus, which can survive without oxygen; and most importantly, Bacillus, which is what gives your belly button that distinctive butthole-crossed-with-expensive-cheese smell. And if you think that's gross, there's also this:
Two samples contained an extremely rare type of archaea, a single-cell organism never previously found on human skin. One of these samples came from a man who self-reported that he had not bathed or showered for several years.
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