What Is the Skin Microbiome?

Medically Reviewed by Stephanie S. Gardner, MD on May 03, 2023
4 min read

Your skin is your largest organ. And it’s teeming with trillions of microorganisms, like bacteria, fungi, and viruses. These invisible life-forms are known as the skin microbiome. They’re an important part of your overall health.

It’s part of a physical layer that protects you from the outside world. It works with other parts of your skin to:

  • Fight infection. Some microbes act like a natural antibiotic. They also help keep your skin acidic, which many germs don’t like.
  • Help your immune system work. Microbes in your skin act as a kind of warning flare, alerting your immune system to harmful bacteria or viruses. They also play a role in how your cells respond to UV light. That’s the kind that causes skin cancer. We need more research, though, to understand how this process works.
  • Heal wounds and control inflammation. Signals from your skin microbiome can activate or de-activate your immune system. That helps you heal and controls harmful inflammation.

Your “core microbiota” are a group of microorganisms that are routinely found in your skin. These microbiota become pretty stable early in life, perhaps when you're about age 3. But they can change.

For example, hormones involved in puberty trigger the release of sebum, the natural oil that coats your skin. Certain bacteria love sebum. That’s why you’re more likely to have acne as a teenager.

The makeup of your skin microbiome varies throughout your body. Some microorganisms thrive in moist areas, like your elbow creases or feet. Others like dry or oily spots.

Some other things that affect your skin microbiome include your:

  • Genes
  • Diet
  • Other lifestyle choices, like smoking
  • Environment
  • Air pollution
  • Exposure to UV light

Some things that happen very early in your life also play a role in your skin microbiome. That includes whether you're born vaginally or through a C-section. Experts aren’t sure how a C-section birth might affect your health over time. But there are ways doctors can transfer vaginal microbes to newborn skin.

Your microbiome can change in ways that aren’t helpful. This imbalance is called dysbiosis. It’s not clear why this happens. But it’s linked to certain health conditions, including:

Researchers are also looking into how the skin microbiome affects conditions such as vitiligo, albinism, dandruff, toenail infections, and warts.

It’s hard to know how much you can change your skin microbiome, especially later in life. But there are some steps you can take to support it, and healthy skin in general:

Don’t over-sanitize. You can upset the balance of your microbiome if you clean your skin too much, especially if you use lots of antibacterial products. Some experts think too much washing raises the odds babies will get eczema. But we need more research on this.

Moisturize. This gives your skin barrier a boost. It's especially helpful for certain skin conditions, like eczema or psoriasis. You don’t have to spend a lot of money on fancy creams. Petroleum jelly works just fine. Just make sure you stay away from harsh ingredients.

Eat a balanced diet. Some research suggests that the microbes in your gut also affect your skin. The way this works isn’t clear. But it's a good idea to eat lots of plant-based foods. Those have prebiotics (indigestible carbs like fiber) that good bacteria really like.

Exercise. Physical activity is good for your overall health. It can also change your gut microbiome in a good way. That benefits your skin microbes, too.

Get out in nature. There’s evidence that green spaces can help our microbiome and boost our mental and physical health.

Treat medical conditions. Skin problems are common when you have certain unmanaged health issues. That includes diabetes and inflammatory bowel diseases, such as Crohn’s disease or ulcerative colitis.

Quit smoking. Cigarette smoking is bad for you in lots of ways. Studies show it can cause inflammation and disturb your skin microbiome.

If you have an imbalance in your skin biome, you may need extra help to get it back on track. That might include oral drugs, creams, or gels to treat any resulting skin conditions. Some experts think supplements like probiotics, which are live "good" bacteria, may help. Ask your doctor or dermatologist what's right for you.