“Good” bacteria are now popping up in serums and moisturizers. Here’s what experts think.
By Melanie Rud
Medically reviewed by Divya Shokeen, MD
“Probiotics” is one of the biggest wellness buzzwords to emerge in recent years, but just in case you’re not familiar with it: The term generally refers to “good” bacteria that live in and on your body, and they come with some research-backed health benefits. The probiotics you can find in supplements and fermented foods have received the most attention, with experts and influencers alike regularly touting them as a panacea for an array of gut issues and a win for your immune system.
But in the last decade or so, these beneficial little bugs have also been proliferating in the skin care world. Topical products with probiotics (serums, moisturizers, cleansers, you name it) are everywhere, and the purported perks range from clearing breakouts to combating dryness.
Admittedly, it all sounds great. But just how legitimate are these claims? Where does the research on topical probiotics stand? And if they’re not the end-all-be-all of skin-saving ingredients, what should you be using instead? We asked a couple of top dermatologists to weigh in.
Let’s start with what we do know: The skin microbiome is a very real thing.
While probiotic skin care comes with a bit of a question mark, there’s no denying that bacteria play a role in your skin health. You’ve probably heard of the gut microbiome, but there’s an external version, too. “Like the gastrointestinal tract, the skin has an ecosystem, or a ‘microbiome,’ which consists of bacteria, fungi, viruses, and mites, all of which help keep the skin barrier healthy and strong,” Robyn Gmyrek, MD, a board-certified dermatologist in New York City tells SELF. “It’s estimated that approximately 1 million bacteria are present per square centimeter of the skin.”
Probiotics are part of this microflora; their function is to help the skin’s microbiome stay in balance by keeping potentially harmful bacteria in check and preventing them from over-proliferating. In turn, that can help to boost barrier health, control inflammation, and prevent water loss in your skin, among other benefits, Ryan Turner, MD, a board-certified dermatologist in New York City and assistant professor at the Albert Einstein College of Medicine, tells SELF.
Similarly, a dysfunctional microbiome is associated with inflammatory skin conditions. Disruption of these microorganisms has been linked to issues like acne, atopic dermatitis (eczema), and rosacea, Dr. Gmyrek says, adding that a bunch of different factors can trigger said disruption, including genetics, UV radiation, and even certain cosmetics.
In theory, there’s a lot that topical probiotics could do for your skin. In reality, it’s complicated.
If the bacteria on your skin is out of balance, adding more of the good stuff should help, right? Theoretically, yes, but when it comes to practical application, the jury’s still out, Dr. Turner says.
“The hypothesis is that we can replace pathogens, or bad bacteria, with good bacteria and replenish and restore the balance of the microbiome, ultimately helping to control inflammation, improve hydration, and help with dry skin, and the like,” he explains. “But the reality is that everyone has a completely unique microbiome and we don’t necessarily know what microorganisms to put on an individual’s skin. It’s not a one-size-fits-all situation.” And, when it comes to probiotic skin care, the majority of the options out there all use the same one or two species of research-backed bacteria—namely, Lactobacilli and Bifidobacterium.
The other potential snafu is product formulation. Things like moisturizers, cleansers, and serums contain necessary preservatives to protect against microbial growth and fermentation, which means that probiotics (which, remember, are live bacteria) will struggle to survive, according to Dr. Turner. Plus, it bears mentioning that topical probiotics aren’t regulated by the FDA. Dr. Gmyrek notes that, because of this lack of oversight, manufacturers don’t have to prove that their products even contain probiotics, so there’s really no way to be certain that a skin care formula is packed with viable microbes. In short, the probiotic claims on moisturizers, serums, and the like are often just marketing hype.
There is some promising research behind topical probiotics, but take it with a grain of salt.
To be fair, a few small studies have explored the potential benefits of probiotic skin care, albeit the results come with some major caveats. One published in the International Journal of Immunopathology and Pharmacology, for example, showed that applying the probiotic Streptococcus thermophilus helped improve hydration in the participants’ skin barriers, Dr. Gmyrek notes. Another study, she adds, indicated that topical use of a high concentration of the bacteria Nitrosomonas eutropha improved visible signs of aging, including fine lines and hyperpigmentation, more than a low concentration.
But, again, these studies were small; the research on the skin barrier included only 20 people, and the study that looked at signs of aging had just 29. Another big limitation: The topical probiotics the scientists looked at weren’t made with the types of added preservatives necessary for store-bought products, Dr. Turner says. Essentially, the formulas aren’t comparable to over-the-counter skin care.
Other skin care practices and ingredients are more tried-and-true.
The bottom line: Both experts we spoke with agree that there’s not quite enough hard-hitting evidence to back the use of topical probiotics. They’re a hot topic in dermatology, but just not well-researched—yet. “The science behind probiotic skin care is still evolving, but it’s not strong enough for me to recommend topical products,” says Dr. Gmyrek, adding that she’d like to see more well-designed clinical trials in order to prove and better understand the potential benefits.
Both she and Dr. Turner also agree that a smarter alternative, as simple as it may seem, is to go back to basics with your skin care routine: Avoid over-cleansing or harsh scrubbing, use products with hydrating ingredients, combat inflammation with topical antioxidants, and address breakouts with derm-backed acne treatments. All of these moves support the skin’s microbiome and, subsequently, the moisture barrier as well, Dr. Turner says—and unlike probiotic skin care, there’s plenty of science to back them up.
