What's in Your Navel? Hundreds and Hundreds of Types of Bacteria

There's more in there than jewelry. chaowalit jaiyen/Shutterstock

When scientists talk about biodiversity hotspots, they're usually discussing places like Madagascar, New Zealand or New Caledonia. But new research proves that one of the richest biodiversity hotspots is much closer: your belly button.

Scientists for the Belly Button Biodiversity project have done a little navel-gazing, studying the belly buttons of 95 volunteers and counting. So far they have turned up 1,400 different bacterial strains, 662 of which appear to be new to science.

"We're probably the only ones studying human belly buttons on such a large scale," project leader Jiri Hulcr, a post-doctoral candidate at North Carolina State University, told msnbc.com.

Even though 1,400 different strains were found, the vast majority — 80 percent — were from 40 more common species.

The amount of belly-button bacteria present on the volunteers varied depending on how well participants scrubbed out their navels on a daily basis. For example, two of the volunteers were journalists for New Scientist magazine. One, Peter Aldhous, washes well and as a result, no bacterial colonies were found in his belly button. But his colleague, Carl Zimmer, was the host of 53 different species of bacteria, one of which had only previously been found in soil samples in Japan.

Volunteers were asked to place long cotton swabs in their navels and turn them around three times. The researchers then placed the swabs in vials and grew the bacteria in cultures. Once the cultures grew big enough, they were photographed and the DNA was extracted for comparison to data on public databases.

Volunteers so far include science bloggers, N.C. State students, and staff at the North Carolina Museum of Natural Sciences. The project took more samples last week at a museum event called The Ecology and Evolution of our Wild Lives.

Why the belly button? Hulcr says it's a novel project that is both lighthearted and illustrative of the nature of our bodies. "The belly button is protected, making it a safe haven for normal skin microbes," he said. That gives all of the bacteria that are normally found on other parts of the skin a chance to thrive, unthreatened by the oils or other secretions produced on other areas of the body.

Want to make sure that there is less bacteria in your own belly button? Wash with soap.