A new study elaborated by researchers from the University of California claims that exposure to the oceanic water can affect the microbiome of the human skin negatively, by altering its structure and composition. When you swim in the ocean, healthy skin bacteria is washed off by the salty water and replaced with ocean bacteria.
Dermal tests proved that all the participants who swam in the ocean featured traces of ocean bacteria, even if 24 hours had passed. In some cases, the number of bacteria was higher, or they were able to survive for a longer time.
The study was based on previous research, which inferred a link between swimming and infections and the fact that many beaches are affected by poor water quality due to wastewater. Changes in the microbiome will increase the chance to get an infection, while also influencing the manifestation of certain diseases.
Swimming in oceans prone us to infections as ocean bacteria replace human skin microbiome
For the sake of the study, several nine volunteers were selected. They met the following criteria: doesn’t use sunscreen, infrequent swimming in the ocean, they didn’t bathe or shower in the last 12 hours, and didn’t take antibiotics in the previous six months. Scientists collected samples from the back of their calf before they went swimming and after 10 minutes, 6 hours and 24 hours had passed.
The results were quite impressive as the individuals featured a similar community on their skin after the swimming, in comparison to different communities at the start of the test. After 6 hours passed the microbiome began to change back to its initial shape, and at 24 hours, the changes were quite visible.
One particular species, the Vibrio, managed to survive on the skin of one individual after 24 hours. While they are not pathogenic, the trait suggests the fact that pathogenic version of ocean bacteria could survive on the skin after swimming.