Antibacterial cosmetics are so last year; the latest craze is for face creams, serums, and washes that actually add bacteria to the skin in order to make it look younger and healthier. But experts think that these products aren’t backed up by enough science to work as their manufacturers claim.
Because they can cause disease and infection, we often think of bacteria as the enemy. But in fact, they are essential to the body’s regular function—colonies of bacteria called the microbiome live in places like the intestines, mouth, vagina, and nose, outnumbering the body’s own cells. Every person’s microbiome is unique, influenced by factors like diet, age, gender, hometown, and family.
Bacteria on the skin play an important role: They are the immune system’s the first line of defense against microbial invaders that could cause disease. The types and concentration of these bacteria vary between different sites on the skin (some thrive in damp, sweaty areas like your armpits while others enjoy the dryness of your forehead).
Now several cosmetics companies claim that they can make skin healthy by restore balance to bacteria that live on the skin, making it healthier. Some products dose the skin directly with live bacteria, while others simply feed the “good” bacteria, leaving fewer resources for the “bad.” Even big names like L’Oreal are investing in microbiome-altering cosmetics. A spokesperson told The Daily Beast that the company is “working with a number of startups and universities to learn about the microbiomes of the skin.”
BioEsse Probiotics is one company with a product intended to tweak the microbiome. In 2011, founders Eva Berkes and Nick Monsol started experimenting with a bacterium called Lactobacillus fermentum, which lives in the gut and is thought to help aid in digestion and ward off attacking microbes. By 2015, they were selling products with the compound derived from it that could help feed bacteria shown to keep the skin functioning properly. “We not only know a lot about the bacterium itself, we know a lot about what it does for the skin,” says Berkes, the co-founder and chief scientific officer of BioEsse Probiotics.
Consumers can buy a serum, lotion, eye cream, or cleanser that contains the compound in order to reduce wrinkles, redness, or inflammation. To show potential customers that the products work, BioEsse conducted a study. Twenty-one participants used two BioEsse products twice per day for 60 days.
According to the results, published on the company’s website (keep in mind: not in a peer-reviewed journal), after eight weeks all participants had a more toned facial expression, while the vast majority thought their skin looked younger and more luminous. “As far as I can tell, we’re the only skin probiotic system that’s actually done clinical studies of the product itself with quantifiable parameters,” Berkes says.
It’s important to note that BioEsse isn’t required to do clinical studies to prove that its product is effective as long as it’s just for cosmetic purposes (The FDA requires tests to make sure the product is safe but not that it’s effective—those kinds of experiments would be necessary if a substance was used for medical purposes).
Still, experts are skeptical about what exactly these data show.
“The ‘clinical study’ does not prove anything,” says Alan Cooper, a geneticist at the University of Adelaide in Australia. Scientifically, the study is lacking—it doesn’t compare BioEsse’s products to anything else, and the small number of participants know that they’re getting something that is supposed to work. Without a control group, you can’t rule out the placebo effect: that just by thinking the products work, participants’ skin “improves.” The data, too, only measured symptoms using a tool that scans the face—there were no measures of the skin bacteria before, during, or after the experiment.
“I’m not sure whether this is any different than using other skin products like [moisturizers]. I couldn’t say that this data would convince me,” says Stanley Spinola, a professor of microbiology and immunology at Indiana University. “[The study] is a nice advertisement.”
But there might be a deeper issue with the science behind BioEsse’s products, and those of other cosmetics companies that claim to alter the skin microbiome. “In some ways we don’t know yet as to whether or not you can change the skin microbiome with a probiotic,” Spinola says. Most sites on the body have microbiomes that are surprisingly stable over time, he adds, an assertion corroborated by a recent study.
Plus, the species of bacteria that could live on a person’s skin are extremely diverse and vary widely even on an individual. With the exception of a few conditions like Staphylococcus aureus disease where the bacteria grow out of control, it’s impossible to tell if a person’s skin is healthy just by analyzing the types and concentrations of bacteria that live on it.
Because scientists don’t even know what a “healthy” microbiome looks like, it’s hard to imagine a substance that could make one healthy again. “Our skin is exposed to the environment all the time. But we all have our own individual microbiome. If we added a probiotic to what is essentially whatever our normal state is, would that make our normal state better? I don’t think there’s any data driving that,” Spinola says.
Spinola doesn’t rule out the possibility that a compound like the one in BioEsse’s products could help restore the bacterial balance to treat some skin conditions. But for now, there’s isn’t enough data to say for sure.
And while BioEsse looks to develop new products based on compounds derived from bacteria that live on tissues that act as barriers inside the body, the company is also collecting more long-term data about their existing products to see if they might be useful to treat medical conditions on the skin.
Without high-quality clinical trials, consumers should be skeptical of adding additional bacterial products to the skin, Spinola warns. But in the end, much of the skin will inevitably come into contact with lots of bacteria—after all, that’s what it’s evolved to do. For those situations, Spinola recommends simple common sense and practicing good hygiene, like washing your hands after you go to the bathroom to rid the skin on your hands of bacteria that could cause disease if they end up in your nose or mouth.
“The environment is the environment, I don’t think we should be afraid of it,” he says.