“Beauty begins in the belly,” is not only the motto of Aussie brand The Beauty Chef, but also a phrase becoming more and more popular with dermatologists looking to help patients with complex skin issues. The reason: “More than 39 trillion bacteria live in and on our bodies, and the majority of them are in the gut,” says gastroenterologist Will Bulsiewicz, MD. “Only 13 years ago, we knew very little about the gut microbiome—the community of microorganisms inside our digestive tract—but a new laboratory technique in 2006 completely opened it up to us for study. What we’ve learned since is that our gut microbes aren’t just along for the ride, thriving off the food we eat; they’re central to our health, and we can’t live without them.”
Not only do they boost our immune system, but Dr. Richard Firshein, integrative medicine expert and founder of Firshein Center, says these microorganisms (predominantly bacteria, aka flora) also have great control over our metabolism and hormones, and even our mood. “Our brains are constantly communicating with our ‘second brain’ in our digestive tracts,” he explains. “For instance, messages from the gut tell the brain when to seek food, while messages from the brain may trigger ‘gut feelings’ in response to stress.”
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To keep the good bacteria thriving and the bad bacteria at bay, we rely on a healthy diet and probiotics. “The word ‘probiotic’ means ‘for life,’” says New York dermatologist Whitney Bowe, MD. “Probiotics are living organisms that support the health of the ‘good bugs,’ or bacteria, that make up our microbiome and sustain the barrier function in our gut. When barrier function is compromised, ‘leaky gut’ can occur, meaning the gut lining allows toxins, undigested food particles and bad bacteria to ‘leak’ out of your intestines and travel throughout your body via your blood. Our immune system marks these foreign substances as threats, and therefore attacks them, leading to substantial health issues.”
In 2008, Jamie Lee Curtis’s Activia ads had us all studying yogurt labels in search of “live cultures.” Since then, kombucha and kefir started taking up space in our refrigerators, and kimchi became the “it” ingredient at five-star restaurants. “Although we can all benefit from eating probiotic-rich foods, that doesn’t mean we should be drinking 32 ounces of kombucha on a daily basis,” says Dr. Bulsiewicz. “A healthy gut is about diversity, not overdoing it on one thing we like.”
Additionally, these “good bugs” aren’t only found in foods: Gastroenterologists prescribe daily probiotic supplements—they’re also available over the counter—to patients to establish a healthier gut, as well as treat gastrointestinal issues such as IBS, bloating and constipation. “Current research also supports their use in weight loss, IBS, depression and anxiety, gut repair after taking antibiotics, food allergy prevention in children, and gastroenteritis, to name a few,” says Dr. Firshein.
“Although probiotics are generally considered very safe, not everyone needs a supplement-strength version, which is typically used with the intention to correct a specific medical issue,” Dr. Bulsiewicz adds. “There’s a lot of room for probiotic science and education to catch up with the hype.”
Perhaps the most widespread use of probiotics is to counteract the effect of antibiotics on our microbiome. “Doctors typically recommend taking the supplements during and after a round of antibiotics to replace the good bacteria the medicine destroyed,” says Dr. Firshein. That daily Diet Coke you reach for around 4 p.m. can also wreak havoc. While artificial sweeteners add no calories to our diet, they do damage the naturally occurring bacteria in our gut, Dr. Firshein explains. “So the problem isn’t just Diet Coke; it’s all the products that use these sweeteners—they’re found in many desserts, cakes and even bread—which cause our bacteria to produce compounds that are toxic to our bodies.”
According to Dr. Firshein, one of the main concerns with taking probiotics is that they are not broad-spectrum enough to fill the needs of the average person. “Considering there are only a handful of strains in most probiotic supplements and up to 1,000 different types of bacteria in our guts, experts question whether ‘unbalances’ could promote the growth of harmful strains in certain individuals, or in some cases, limit the variations in the gut biome that a healthy person needs.”
It is scientifically established that gut health has a strong impact on skin health. “If the good and bad bacteria aren’t balanced in your gut, then conditions can result,” says gastroenterologist and founder of TULA Skincare, Roshini Rajapaksa, MD. “I was inspired to research the topical benefits of probiotics after noticing how much better my patients’ skin looked once their health had improved with oral probiotic treatments.”
What Dr. Rajapaksa learned is that our skin has its own microbiome, which acts as its first layer of defense from climate changes, pollution, sweat and other assaults. “The skin microbiome is amazing, adaptive and resilient when it’s healthy, but fragile when it’s not,” says Jeff Rosevear, founding scientist and head of product development for SKINSEI, a prebiotic skin-care line. “Everyone has a unique skin microbiome because it is the result of everything an individual’s skin has been exposed to over the course of their lifetime.”
Dr. Bowe explores this further in her book, The Beauty of Dirty Skin: “We know about ‘leaky gut,’ but there’s also ‘leaky skin,’ which is the compromise of our skin’s natural barrier due to an unbalanced skin microbiome,” she says. “Our obsession with antibacterial soaps and high pH cleansers often strip our skin of its healthy bacteria, which causes inflammatory issues and sensitivity.” In 2016, the FDA banned the use of triclosan in antibacterial soaps, affecting nearly 2,100 products. Manufacturers have since removed the ingredient from other products too, including toothpaste. “It can kill off healthy bacteria in some and promote drug resistance in others,” says Dr. Bowe. “Additional ingredients that can affect the skin microbiome include sulfur, benzoyl peroxide, sulfates, and high levels of harsh alcohols, surfactants or preservatives.”
However, this science is very new, and experts are just learning how each ingredient affects the microbiome. “For example, certain preservatives at low concentrations might only create a very transient dip in certain strains, and people with healthy skin might be able to recover within minutes or hours of exposure,” Dr. Bowe explains. “These are all questions companies are researching right now—Dove is conducting tests to ensure its cleansers don’t induce negative changes in our microbiome over time; Mother Dirt is using a live, ‘peacekeeper’ strain of bacteria to restore essential bacteria that have been removed by modern hygiene. It’s not enough to be clean these days; brands also want to be biome-friendly.”
Hence, the surge in prebiotic and probiotic products, which have anti-inflammatory effects on the skin (effects on the scalp are also being studied). This makes them a great option for those with acne, redness, psoriasis, dry skin and/or eczema—“when used topically, lactobacillus plantarum has been proven to decrease the number and size of acne lesions, as well as redness, and may also help with rosacea flares,” Dr. Bowe says. But, it’s important to know that topical probiotics aren’t a magic bullet for eliminating inflammatory conditions. “The challenge with this category of skin care is that many consumers are focused on immediate results,” says Rosevear. “They need to shift their mindset to think more about the long-term benefits of an anti-inflammatory regimen.”
Some interesting tools are also emerging that may allow prebiotic and probiotic skin-care products to become more personalized and effective. “A handful of companies are researching the ability to test an individual’s gut and skin flora,” says Dr. Bowe, comparing the technology to that of genetic testing companies like 23andMe. “For example, ProdermIQ can analyze the bacteria that exist on your skin after a single swab. The hope is to use this data to develop customized, efficacious skin-care lines.”
One frequently asked question is whether or not products that contain probiotics will “die” if they aren’t refrigerated. Rosevear explains that preservatives can kill live bacteria, which is why it is difficult to formulate skin-care products with them because they’d require refrigeration, and most of us aren’t willing to do that. (However, with mini skin-care refrigerators becoming deskside staples, this could soon change.) To circumvent this issue, Dr. Rajapaksa says many companies, including her own TULA Skincare, have found a way to “extract the beneficial metabolites—postbiotics—from probiotic bacteria, isolating the specific actives that are effective on the skin. This ensures our products remain both shelf-stable and effective without the need to refrigerate,” she says.