Belly Buttons: Unexplored Territory Until Now

No! This is not my belly button. Photo courtesy: hweiling / cc

After decades of exploring the wealth of biodiversity found in some of the planet's remotest ecosystems, from high atop the forest canopy, to down deep within the ocean's murky depths, scientists have now turned their attention to one of the darkest, most foreboding places of all -- your belly button!

Sure, that little built-in lint trap might not seem so terribly interesting, aside from being a battle scar from the early days of our infantile independence. But for a team of researchers, lead by Dr. Robert Dunn, delving into the human belly button is actually like visiting a unknown world. And they should know; they've bravely participated in dozens of harrowing navel expeditions in search of new life.

That is to say, they've swabbed and cultured bacteria samples from 60 participants across the U.S. -- discovering in the process more than 2,000 distinct species, some of which are quite uncommon.

"As we looked at belly buttons we saw a terrible, yawning, richness of life," writes Dr. Dunn. "The average belly button hosted 50 or so species and across belly buttons we found thousands of species (and as we sample more belly buttons, we continue to find more species). The vast majority of these species are rare. Right away something struck an ecological chord. The belly buttons reminded me of rain forests."

Interestingly enough, despite the broadness of their sampling, Dunn and his team found that the commonest species found were present in around 70 percent of belly buttons tested -- though no one bacteria was present in all of them.

"Although it remains difficult to predict which species of bacteria might be found on a particular human, predicting which species are most frequent (or rare) seems more straightforward, at least for those species living in belly buttons," researchers write in their study, appearing in the journal PLOS ONE.

What Dunn and his team failed to uncover, however, was why each person's navel seems to be so distinct -- conceding: "what we cannot seem to account for is which species are present in any particular belly button."

But that should come as no surprise; scientists have really only begun to poke around the belly button just recently and there's certainly far more to learn.

"The belly button is one of the habitats closest to us, and yet it remains relatively unexplored."