Dear Doctors: I heard two teenagers at the drugstore talking about the skin microbiome and how you shouldn’t use soap on your face because it wipes out the good bacteria. Is the skin microbiome really a thing?
Answer: Microbiome refers to any community of microorganisms that live together peaceably in a specific environment. To reflect that they don’t cause illness, it’s said they colonize rather than infect an area.
In terms of the human microbiome, we’re talking about the vast array of microbes that live on and in our bodies. These typically are composed of bacteria, bacteriophages, fungi, protozoa and viruses.
In addition to the gut, there are distinct microbiomes in and around the nose, mouth, esophagus, lungs, genitals, the belly button and, yes, the skin, which has multiple microbiomes that, depending on their locations, are affected by the environment they interact with.
The skin between your toes, which spends long stretches in the moist darkness created by socks, shoes and perspiration, hosts different microbes than the skin on your scalp, behind your ears or on the backs of your hands.
The epidermis — the top layer of the skin — is a tough environment for microbes. It’s dry, acidic and low in nutrients, and great swaths of it are exposed to the elements. Yet millions of bacteria, viruses and fungi make it their home.
They survive on the available proteins, oils, salt or moisture. Research shows that, as with our gut, many of the microbe colonies on our skin help fend off pathogens. They also play a role in wound healing and how we smell.
Dermatologists say harsh soaps, too much scrubbing and daily bathing with overly hot water can strip the epidermis of helpful oils and wreak havoc on beneficial microbe colonies.
So think in terms of gentle, pH-balanced soaps, and save the scrubbing with loofas and brushes and other rough materials for the truly grubby areas. Instead of a vigorous rubbing with a towel after bathing, gently dab and pat dry your skin.
Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health.
