#Skin deep skin skin#

Segre and Belkaid are convinced that humans do receive a net gain from their skin biota. Researchers have not yet settled the question of how much human beings benefit from their microbial hangers-on. aureus to the nasal tissue that it often inhabits, the human host could be in for dangerous skin and soft tissue infections. Belkaid and Segre speculate that 'profound changes' in the human skin microbiota may contribute to the increase in chronic inflammatory and autoimmune disorders seen in high-income countries.' Eczema prevalence has doubled in industrialized countries, possibly because of environmental pressures on the skin biota, such as increased usage of antibiotics, less exposure to environmental microbes in soil and water, and more conditioned environments.

If the microbiota is sick, the human host will probably get sick, too.ĭysbiosis has long been associated with skin disorders such as atopic dermatitis (eczema), psoriasis and the teenage bugaboo, acne. They really do not perceive that there is a benefit to the microbes that reside on their skin.'Ī potential downside, of course, is that any disturbance of the fine balance of the skin microbes-called dysbiosis-can be costly. 'Whereas on their hands, all people want to do is use hand sanitizer and sterilize themselves. 'Humans want to eat yogurt because they have the concept that the microbes in their gut are providing a benefit,' said Dr. Most people don't realize the skin microbiota's contribution to their well-being. In fact, the richest concentrations of immune cells in the body are at sites populated by commensal cells, and the skin is 'one of the largest reservoirs of memory T cells in the body,' Drs. Among these functions are overall immune system screening, tissue repair, wound healing, inflammation control, production of defensive anti-microbial peptides (AMPs), acceleration of the complement arm of the immune system, regulation of interleukin-1 (IL-1), and modulation of T cells, key actors in directing immune system response. Other skin microorganisms perform a wide variety of functions that help out their host. aureus, the source of many hospital-acquired infections that in its methicillin-resistant form is known as the 'superbug' MRSA. epidermidis also inhibits tissue colonization by the highly pathogenic S.

The underlying advantage, of course, is that the microorganisms that live on human skin-called commensals - have evolved to defend their dwelling place - us.įor example, the skin bacterium Staphylococcus epidermidis produces a secretion that reduces inflammation and speeds wound healing by binding to an immune-system receptor. 21, 2014, issue of Science, Julie Segre, Ph.D., head of the Microbial Genomics Section of the National Human Genome Research Institute (NHGRI), and Yasmine Belkaid, Ph.D., head of the Mucosal Immunology Section of the National Institute of Allergy and Infectious Diseases (NIAID), sum up what researchers have learned so far about the advantages, and some of the downsides, of this intimate partnership.