- If a person has an "innie" belly button, this moist, warm space can be home to well over 100 different organisms.
- Bacteria, fungi and yeasts are among the different types of belly button organisms.
- Microbial mixes differ between individuals, but benefit all of us by helping to fight off pathogens.
If you're an innie and not an outie, your belly button is home to at least 60 to 100 or more species of bacteria, fungi and yeasts, according to new research.
The findings, to be presented on Aug. 12 at the Ecological Society of America's 96th Annual Meeting in Austin, Texas, demonstrate how a belly button can become a haven for complex biodiversity.
"Although we find about 60 or 70 species on the average person, we have found more than 1400 species overall, such that differences among individuals are great," Rob Dunn, assistant professor in the Department of Biology at North Carolina State University, told Discovery News.
Dunn and his colleagues have so far collected skin bacteria from the belly buttons of 391 test subjects from across the nation. Men and women of different ages and ethic backgrounds, and even differing hygienic habits, were included in the study. The researchers have been focusing on bacterial content within the samples, but "there are also fungi and some interesting yeasts," Dunn said.
The scientists have confirmed the viability of these organisms by culturing, and are now in the process of sequencing each species' DNA.
Preliminary results indicate that the number of organisms per person highly varies, with each individual carrying his or her own unique mix.
"So far, we don't see clear explanations for why people differ so much in terms of their bacterial communities from person to person," Dunn said. "The differences we see don't match up easily with gender, ethnicity, age or even washing frequency. Something else is going on."
The researchers have, however, concluded that a group of relatively few bacterial species are shared among most of us, with hundreds of other rare species occurring here and there.