As we have repeatedly emphasised on these pages, bacteria are important for our skin’s natural protection. Excessive or incorrect skin care may damage this natural barrier. The result: Our skin becomes vulnerable to infections, even though or rather precisely because it is kept “clinically” clean.
A team of scientists at the National Institute of Allergy and Infectious Diseases in Bethesda has found that healthy bacteria not only provide external but also internal benefits. Not only do they protect our skin as a barrier against skin diseases, they also stimulate our immune system in the body.
The journal “Science” reported on the US team’s experiments with two groups of mice. One group had microbes present on their skin. The other group had been raised in a sterile environment; as a result, their skins were ‘germ-free’. Examination of the animals showed that skin bacteria are not only responsible for our outer defence, but also for the inner defence. More specifically, the so-called T-cells (or T-lymphocytes) which are in charge of the body’s immune system were less active among germ-free mice and the animals were thus less well protected against pathogens.
Previously, we had only been aware that diversity and composition of gut bacteria influenced our immune system. The studies referred to above have shown that skin bacteria also have an impact on our immune system.