Staying in the sun harms the skin microbiome
The negative effects of the sun's ultraviolet rays have long been proven: they damage DNA in cells, cause inflammation and premature aging of the skin. There are also studies showing a link between exposure to ultraviolet radiation (UVR) and the development of skin cancer. Nevertheless, people still tend to spend a lot of time in the sunlight, neglecting protection, particularly SPF. Recently, a team of scientists from the UK published a new paper showing results obtained on a group of vacationing tourists: sunburn significantly affects the diversity and composition of the skin's microbiota, wiping out populations of beneficial, protective bacteria. But the good news is that these populations gradually rebound after a vacation and, consequently, a reduction in time spent in the sun. The research paper is published in the journal Frontiers in Aging.
The skin is the largest human organ and is home to a huge number of bacteria, fungi and viruses - the microorganisms that make up the skin microbiota. These microbes, among other things, protect the skin from pathogens. The microbiota on the surface of the skin is mainly composed of three bacterial communities: actinobacteria, proteobacteria and Firmicutes.
The experts analyzed the composition of bacteria on the skin of a group of vacationers before a vacation lasting at least seven days and three times after it. They also assessed the degree of tanning of the participants - depending on this, the subjects were divided into groups: "sun seekers" and "sun avoiders".
It turned out that people who liked to tan during their vacation and, accordingly, changed their skin tone, showed a significant reduction in the population of Proteobacteria, which reduced the diversity of the skin microbiota, and therefore reduced the protective function of the organ.
Despite this, 28 days after people returned from vacation, the structure of this bacterial community had significantly recovered.
"This study was conducted on real vacationers and provides important information on how sun exposure leading to tanning, even for a relatively short period, can lead to a dramatic reduction in Proteobacteria populations," says Thomas Willmott, first author of the study.
Thus, UV exposure during a vacation has a profound effect on the skin's microbiota. However, recovery occurs relatively quickly when a person returns to a less sunny climate.