Swimming in the ocean alters the microbiome of the skin and may increase the likelihood of infection, as demonstrated by research at the annual meeting of the American Society for Microbiology (ASM Microbe 2019).
"Our data prove this for the first time Exposure to seawater can alter the diversity and composition of the microbiome of human skin," said Marisa Chattman Nielsen, MS, a PhD student at the University of California at Irvine, lead author of the study. During swimming, normal bacteria were washed off while marine bacteria were deposited on the skin.
Researchers discovered marine bacteria in all participants after air drying and six and 24 hours after swimming, but some participants had acquired more marine bacteria and / or allowed them to last longer.
Research was motivated by previous studies showing links between marine life and infection, as well as the high prevalence of poor water quality at many beaches due to sewage and rainwater runoff. Recent research has shown that changes in the microbiome can make the host susceptible to infection and affect disease states. Exposure to these waters can cause gastrointestinal and respiratory diseases, ear infections and skin infections.
The investigators looked for 9 volunteers on a beach who met the criteria of not using sunscreen, less exposure to the ocean, no bathing in the last 1
Before swimming, all individuals had different symptoms of the communities of each other, but after swimming they all had similar communities on the skin that were completely different from the communities before swimming. Six hours after swimming, the microbiomas had begun to return to their pre-swimming composition, and after 24 hours, they had progressed well in this process.
"A very interesting finding was that Vibrio species – identified only at the level of the genera – were found in each participant after swimming in the sea and air-drying," said. Nielsen. (The genus Vibrio includes the bacterium that causes cholera.) Six hours after swimming, they were still present in most volunteers, but 24 hours later, they were only present in one person.
"While many Vibrio are not pathogenic, the fact that we salvaged them after swimming on the skin shows that pathogenic Vibrio species may be on the swim after Skin can remain, "said Nielsen. The proportion of Vibrio species detected on human skin was more than ten times higher than that in the ocean water sample, indicating a specific affinity for attachment to human skin.
Skin is the first line of the body's defense, both physically and immunologically, in contact with contaminated water. "Recent studies have shown that the microbiome of human skin plays an important role in the functioning of the immune system, in localized and systemic diseases and in infections," said Nielsen. "A healthy microbiome protects the host from colonization and infection by opportunistic and pathogenic microbes."