The human skin is home to about a thousand species of bacteria and other microbes, collectively called the skin microbiome. Many of these are important for health.
https://www.nih.gov/news-events/nih-research-matters/compound-produced-bacteria-protects-skin#:~:text=The%20human%20skin%20is%20home,of%20other%2C%20potentially%20harmful%20microbes.
Beneficial skin bacteria can prevent the growth of other, potentially harmful microbes. Studies have also shown that some skin bacteria interact with the immune system to help fight infection.
Soruce : National Institutes of Health