MICROBIAL communities on the skin remain unchanged even after coming into contact with bacteria, fungi, and viruses from external sources, researchers have found. It is thought that the new discovery could help to advance our understanding of the localisation of skin disorders such as acne, eczema, and psoriasis.
The study examined the genetic makeup of microbes in skin samples from 17 sites on the body from 12 healthy volunteers. The samples were taken at three successive intervals, between 1 month and 2 years apart. To analyse the samples, a technique called metagenomic shotgun sequencing was employed.
The results showed, unexpectedly, that in spite of the influence of bacteria, fungi, and viruses from other people, clothing, surfaces, and objects, the microbial communities remained stable at each site of the body. Dr Julie Segre, Translational and Functional Genomics Branch, National Human Genome Research Institute (NHGRI), US National Human Genome Research Institute, Bethesda, Maryland, USA, explained that “an individual’s short and long-term community similarity significantly exceeded similarity between individuals,” and that these results resemble “observations in gut and other communities.”
They also found, however, that different strains had different variability and that the communities varied between different people. Microbes at oily sites including the back and the outer to middle ear canal were found to vary the least over time. Similarly, those on highly exposed and dry sites such as the palms remained the most stable. Skin areas with larger and more diverse communities, such as the feet, were found to be a lot more changeable over time. The team hypothesised that this could be due to the personal hygiene habits of patients or to exposure to a greater number of environments.
Following the study, the team plan to widen their investigations to address the small number of patients who were studied. The next study may include patients with eczema and skin disorders as a result of a missing part of the immune system. Dr Segre commented, “Future studies can use the knowledge of the relative stability of the skin microbial communities in healthy adults to understand how various exposures or disease state may alter these skin microbes.”