How Do Topical Probiotics Actually Work?

On introducing bacteria to your skin-care regimen

Illustrated by Lindsay Hattrick

Probiotics, or “good” bacteria, have been a buzzy subject in the health and wellness space for some time now, particularly as we learn more and more about the importance of maintaining a healthy gut and how that microbiome affects the rest of our body, including our skin.

But, on top of the growing popularity of ingestible probiotic products, such as yogurt and fermented foods, powdered and pill supplements, kombucha, and more, we’re now seeing probiotics pop up in our skin care. But the question is: Do they actually work? We talked to several doctors and beauty professionals to find out the dirt, so to speak, on probiotic skin care and our microbiomes, in general.

First things first, what even is a skin microbiome?
Much like our gut, our skin is also inhabited by a number of “healthy” bacteria, yeast, and viruses, which are collectively known as the skin microbiome. “A healthy microbiome is essential for optimal skin and gut health,” says Dr. Pearl Grimes, dermatologist and president of the Women’s Dermatologic Society. “The healthy organisms at both sites suppress the detrimental effects of natural residents or invading microorganisms.”

However, our skin’s microbiome can easily become disrupted and thrown off balance. As Grimes explains, a variety of factors can contribute to this imbalance, including skin-care products we use daily, like soaps and moisturizers that contain harsh ingredients. Other things that could wreak havoc on our microbiomes, according to Margo Weishar, M.D., of Springhouse Dermaesthetics, include environmental stress (hello, pollution!), acne treatments, and skin conditions, like eczema, that affect our skin's barrier functions. If all that seems overwhelming, don't worry—there are remedies available.

Is this where probiotics come in?
Yes! In fact, there are three different categories of treatments to help regulate your microbiome, which Weishar breaks down for us: “Prebiotics are composed of substances that help promote the growth of helpful bacteria, while probiotics contain the actual bacteria. Lastly, there are postbiotics, which contain substances produced by bacteria that are helpful to the skin.”

Out of these three, probiotics have become the best-known, coming to the rescue as a means of rebalancing the skin by introducing helpful bacteria missing from our microbiomes.

So are all topical probiotics just a means of slathering living bacteria on our faces?
No! Actually, not all probiotics are the same—they don't even all contain living bacteria. As David Pollock, beauty chemist, consultant, and the brains behind Just Ask David, explains, many products have preservative systems which kill the live bacteria microbes, making the cultures deactivated—but still effective. “The challenge is how to bring out the benefits of fermentation and probiotics when the microbe is no longer live,” he says. So while, yes, probiotic skin care involves putting products full of bacteria on our skin, some products, such as Mother Dirt, contain living cultures, while other brands, like Aurelia, contain deactivated bacteria.

But what are the specific benefits of topical probiotics?
Dr. Grimes says that “topical skin-care regimens containing probiotics have been shown to establish a healthy skin pH, reduce inflammation, reduce the deleterious effects of pollution on the skin, as well as functioning as skin antioxidants."

Additionally, Grimes says that many people with specific skin concerns should look into using probiotics: “Recent studies have shown that probiotic strains have the ability to reduce abnormal pigmentation and improve fine lines and wrinkles. Skin conditions that have been shown to benefit from topical probiotics include atopic dermatitis, acne vulgaris, acne rosacea, sebhorrheic dermatitis, and psoriasis.”

As Weishar explains, many acne treatments work by killing all bacteria on the skin—both bad and good. This can cause even more problems, though, and some think that probiotics allow the skin to learn how to regulate itself better. Weishar says, “I’m very excited by the idea of using a patient’s natural ecology of bacteria on the skin to help fight acne, rosacea, eczema, and more to help promote a beautiful, glowing complexion. It’s wonderful to use the body’s own knowledge to heal itself.” 

But is it safe to put bacteria on your skin?
Grimes says that, as with all skin-care products, some individuals may experience some minor irritation. So test individual products for a while before committing to their use. 

Something to keep in mind is that, as with many clean and natural skin-care products, products containing live probiotics will have a relatively short shelf life. Astarita urges you to check the box or the product itself for an expiration date to ensure effectiveness—and to be sure a product hasn’t spoiled.

You should also treat probiotic skin-care products the same way you would treat ingestible probiotics—by either keeping them refrigerated or in a very cool place, as well as follow any specific brand recommendations, suggests Grimes.

Curious to give probiotic skin care a go? Check out some of our most trusted products, below.

Photo courtesy of Biossance

Biossance, Squalane + Probiotic Gel Moisturizer, $52, available at Biossance.