The Microbiome of Your Skin

Part of The Secret World Inside You exhibition. 

Your skin is the largest organ of your body. It is also a diverse microscopic landscape.

Lots of Neighborhoods

Skin makes for a sprawling countryside of hills and valleys, cracks and crevices, smooth slopes and rough terrain. In each of these regions, you can find a variety of bacteria, fungi, and other microbes making themselves at home.

Your skin hosts a wide variety of microbes in huge numbers, but populations can vary among individuals.
© AMNH/B. Peterson

Differences in skin temperature, texture, thickness, humidity, and chemistry help determine which kinds of microbes live where.

Similar parts of your body can host very different microbiomes. For instance, the microbiomes of left and right hands are not the same. One hand may be sweatier or oilier than the other, and the two often touch different objects.

Rod-shaped bacteria congregate at oily spots, where they use your body’s oils for fuel.

Dandruff-causing bacteria live on parts of the skin with many oil glands, like the scalp.
© AMNH/B. Peterson

Warm, wet areas of the skin—your armpit, for instance—host bacteria that break down sweat, many of which release unpleasant odors in the process.

Microbes Come and Go

Players can find their skin micro biomes changed by contact with one another during a roller derby bout.
CC/ E. McGehee

Your skin is where your body meets the rest of the world. When you touch a surface, your skin picks up many new microbes, and leaves others behind.

Contact with your family, your pets, and the things you touch in the course of a day means you’re continually introducing new microbes to the mix.

To illustrate this, a study of roller derby players found that after a bout—which involves lots of bumping between skaters—the skin microbiomes of everyone involved in play became more similar.

Turf Wars

A larger-than-life depiction of bacteria fighting the fungus that causes athlete’s foot on display in The Secret World Inside You.
© AMNH/R. Mickens

The microbes living on and in your skin enjoy shelter, moisture, and the chemical building blocks they need for growth. They also get nutrients like sugars, vitamins and amino acids from many materials found in skin. Their turf is valuable, and they will fight to defend it.

One example of these microbial melees is the condition known as athlete’s foot, which is caused by a fungus. The bacteria Bacillus subtilis, though, occupies the same space on skin, and keeps the fungus at bay. 

Return to The Secret World Inside You main exhibition page.