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.
"It may be that we mostly share our common species, but that the rare species we encounter are a measure of our individual stories and are inherently unpredictable," he said.
The researchers chose to look at belly buttons, in part, because they tend to harbor so many organisms that are often undisturbed by cleansers, lotions, ultraviolet light and other things.