Normal bacteria on skin surface healthy: study
November 24, 2009 2:41 am
LOS ANGELES, Nov. 23 — Normal bacteria living on the skin are good for our health, a new study has found.
According to a study by the University of California, San Diego (UCSD) School of Medicine, bacteria are abundant, diverse and constant on the skin's surface and they help maintain balance in the skin
The researchers say the bacteria trigger a pathway that prevents excessive inflammation after injury.
"These germs are actually good for us," said Richard L. Gallo, professor of medicine and pediatrics, chief of UCSD's Division of Dermatology and the Dermatology section of the Veterans Affairs San Diego Healthcare System.
The study is to be published in the advance on-line edition of Nature Medicine on Sunday.
The study was primarily conducted by post-doctoral fellow Yu Ping Lai in mice and in human cell cultures.
Gallo said the exciting implications of Dr. Lai's work was that it provided a molecular basis to understand the "hygiene hypothesis" and had uncovered elements of the wound repair response that were previously unknown.
He said this might help scientists devise new therapeutic approaches for inflammatory skin diseases.
The "hygiene hypothesis" was first introduced in the late 1980s. It suggests that a lack of early childhood exposure to infectious agents and microorganisms increases an individual's susceptibility to disease by changing how the immune system reacts to such "bacterial invaders."
The hypothesis was first developed to explain why allergies like hay fever and eczema were less common in children from large families, who were presumably exposed to more infectious agents than others.
It is also used to explain the higher incidence of allergic diseases in industrialized countries.
Researchers said the skin's normal bacteria included certain staphylococcal bacterial species that would induce an inflammatory response when they were introduced below the skin's surface, but did not initiate inflammation when present on the epidermis, or outer layer of skin.
Lai, Gallo and their colleagues also revealed a previously unknown mechanism by which a product of staphylococci inhibits skin inflammation. (PNA/Xinhua)
DCT/ebp
Comments