NEW YORK, Feb. 5, 2007It appears that the skin, the largest organ in our body, is a kind of zoo and some of the inhabitants are quite novel, according to a new study. Researchers found evidence for 182 species of bacteria in skin samples. Eight percent were unknown species that had never before been described.
It is the first study to identify the composition of bacterial populations on the skin using a powerful molecular method. Not only were the bacteria more diverse than previously estimated, but some of them had not been found before, says Martin J. Blaser, M.D., Frederick King Professor and Chair of the Department of Medicine and Professor of Microbiology at NYU School of Medicine, one of the authors of the study.
"The skin is home to a virtual zoo of bacteria," he says. This study is published February 5, 2007, in the online edition of the Proceedings of the National Academy of Sciences.
The researchers analyzed the bacteria on the forearms of six healthy subjects; three men and three women. "This is essentially the first molecular study of the skin," says Dr. Blaser. The skin has been, he says, terra incognita, an unknown world that he and his colleagues have set out to understand much like explorers.
"There are probably fewer than ten labs in the U.S. looking at this question," says Dr. Blaser. "It is very intensive work," he adds. Zhan Gao, M.D., senior research scientist in Dr. Blaser's lab, led the research, which took more than three years to complete.
Some of the bacteria on the skin appear to be more or less permanent residents; others are transient, according to the study.
This research is part of an emerging effort to study human microbial ecology. Dr. Blaser's laboratory has previously examined the bacterial population in the stomach and the esophagus. "Many of the bacteria of the human body are still unknown," he says. "We all live with bacteria all our lives and occasi
Contact: Jennifer Berman
New York University Medical Center and School of Medicine