Hirsch noted that the results of the study -- which are a work in progress and have not undergone peer review -- are not detailed and did not yield many conclusions. But he said most bacteria are good "and their very presence crowds out more dangerous bacteria."
"I'm amazed at how the body responds to infection and how often we see spectacular successes in the way it responds," he said. "The human body is incredible. When we look at it from a bacterial perspective, it's like a new world."
Philip M. Tierno Jr., author of The Secret Life of Germs and director of clinical microbiology and immunology at NYU Langone Medical Center, said it's not news to him that there's a greater diversity of bacteria on the skin than many people think.
The number and types of microbes found in belly buttons may not be representative of what's found on the rest of the human body because of its depth, where lint and other "cellular debris" can accumulate, said Tierno, also a clinical professor of microbiology and pathology at New York University School of Medicine.
"Only 10 percent of you is you, which should give you an idea of how important microbes are," he said. "Ninety percent is bacteria or microbial cells, although body cells are bigger."
The University of Maryland Medical Center has more information about skin bacteria.
SOURCES: Bruce Hirsch, M.D., attending physician, infectious diseases, North Shore University Hospital, Manhasset, N.Y.; Philip M. Tierno Jr., Ph.D., director, clinical microbiology and immunology, NYU Langone Medical Center, and clinical professor, microbiology and pathology, New York University School of Medicine; Aug. 12, 2011, prese
All rights reserved