Skin Bacteria could Protect against Disease

Propionibacterium acnes. Credit: Matthias Mörgelin, Lund University

Rolf Lood from Lund University in Sweden has shown that the most common bacteria on human skin, Propionibacterium acnes secrete a protein which protects us from the reactive oxygen species thought to contribute to several skin diseases. The protein has an equally strong effect on dangerous oxygen species as known antioxidants eg vitamin C and E.

“The name originates from the fact that the bacterium was first discovered on a patient with severe acne. But whether it causes acne is uncertain – it may have been present merely because it is so common,” says Rolf Lood, Lund. He has discovered that the “acne bacterium” secretes a proteinm RoxP. This protein protects against oxidative stress, a condition in which reactive oxygen species damage cells. A common cause of oxidative stress on the skin is UV radiation from the sun.

“This protein is important for the bacterium’s very survival on our skin. The bacterium improves its living environment by secreting RoxP, but in doing so it also benefits us,” explains Rolf Lood. Oxidative stress is considered to be a contributing factor in several skin diseases, eg atopic dermatitis, psoriasis and skin cancer.

RoxP significantly facilitates the survival and colonization of P. acnes in oxic environments.

People have different amounts of the bacterium on their skin, and it can also produce more or less RoxP. This will now be further investigated in both patients and laboratory animals by Lood and his team. The human study will compare patients with basal cell carcinoma, BCC, a pre-cancerous condition – actinic keratosis and a healthy control group. The study will be able to show whether there is any connection between the degree of illness and the amount of RoxP on the patient’s skin.

The study on animals will also examine whether RoxP also functions as protection. Here, mice who have been given RoxP and others who have not will be exposed to UV radiation. The researchers will then observe whether the RoxP mice have a better outcome than those who were not given the protective protein. “If the study results are positive, they could lead to the inclusion of RoxP in sunscreens and its use in the treatment of psoriasis and atopic dermatitis,” hopes Rolf Lood. http://www.lunduniversity.lu.se/article/skin-bacteria-could-protect-against-disease