Friday, November 23, 2012


Research scientests found 2368 species of bacteria in the bellybuttons of 391 volunteers.  1458 of these may have been previously unknown.

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.

Some belly buttons harbored as few as 29 species and some as many as 107, although most had around 67. Ninety-two percent of the bacteria types showed up on fewer than 10 percent of subjects—in fact, most of the time, they appeared in only a single subject.  Even though not a single strain showed up in each subject, eight species were present on more than 70 percent of the subjects. And whenever these species appeared, they did so in huge numbers.

They included strange species, such as one found in the researcher's navel that appears to prefer to break down pesticides.  Another participant harbored a species of bacteria previously found only in Japan -- a place neither he or his family had ever visited.  And one subject, who admittedly hadn’t washed for years, hosted two species of bacteria that typically thrive in ice caps and thermal vents.

They include a bacillus that produces antibiotic compounds that can kill other bacteria as well as foot fungi, and a type of clostridial bacterium. The latter’s diverse family includes botulism and gangrene bacteria, along with many harmless bugs.

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.

This picture shows some:  Micrococcus, Clostridiales, Staphylococcus, Bacillus

study website:

article about the bacteria found:

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  1. What's interesting is how common it was for people to have a large volume of life in their navels. Half of the test subjects had higher than the median amount.

  2. Before I read the bit about the rain forest, I had already made the comparison in my mind. No, really. :) I was thinking that a trip to one's navel is a lot less expensive and dangerous than a trip down to the Amazon. But a lot less interesting and fun.