Our belly buttons contain a "rainforest of bacteria"

You might not think your belly button and a rainforest have anything in common, but scientists revealed that they actually do.

In 2011, the Belly Button Biodiversity project began at North Carolina State University. After an undergrad expressed an idea to explore what's in belly buttons, biologists at the university decided to take it seriously. They took swabs of 60 volunteers' belly buttons, and what they found intrigued them so much that they decided to continue their research.

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The team found over 2,000 species in their navels -- and more than half of them could be new to science. There were on average 67 species present in the belly button; some people had as few as 29 and as many as 107.

There were no species that showed up in every single sample, but eight species appeared in over 70 percent of samples. If any of those eight species were present, it was probably in large numbers. Many species, however, only showed up in one person.

"That makes the belly button a lot like rain forests," said Dr. Robert Dunn, ecologist at North Carolina State University.

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"The idea that some aspects of our bodies are like a rain forest—to me it's quite beautiful," he continued. "And it makes sense to me as an ecologist. I understand what steps to take next; I can see how that works."

Given that the team found potentially new species, they will continue their work. They hope to found out what these species are and how they affect human health, if at all.