The Science Behind Embracing & Nourishing The Full-Body Biome
We've always believed that caring for yourself starts with intention: Coming to understand and appreciate your unique needs as a person can help you live a healthier, more balanced life. But being intentional, at its core, is about educating yourself on how your body works.
And with time, we've come to understand a core aspect of taking care of yourself is tending to your microbiome. Yes, the world of organisms that live in and on you is part of you, and part of your health. It's time we home in on exactly how to care for them.
What is the microbiome?
The microbiome refers to the world of bacteria, fungus, and microorganisms living on and in you. And the health and diversity of this flora, it turns out, has some impressive influence over the body. In general, the microbiome plays a huge role in immune function. This is true of both the skin and gut biomes, as much of your immune system operates in both of these areas.
Now for the skin microbiome, in particular, we see several additional benefits. "As the largest and most visible organ, the skin not only gives clues into what's happening beneath the surface in terms of immune function, nutrition, oxidative stress, and metabolic issues, to name a few, but it's the body's first line of defense against infection, environmental stressors, and loss of nutrients and water. So addressing the skin is a gateway to overall health and well-being," says board-certified dermatologist Keira Barr, M.D. "The skin microbiome is constantly interacting with our environment and works to support our health by protecting against infection, influencing the immune response, protecting against UV radiation, and helps provide nourishment to the skin cells."
What are "eco-niches"?
While the microbiome is a collective, it is not a monolith. Within the flora ecosystem, there are specific eco niches formed at specific areas around the body: the armpits, elbows, knees, feet, scalp, face, mouth, and genitals. This is because these areas create unique environments, which attract their own array of organisms. Additionally, these eco niches are further affected by your hormones, age, lifestyle, and so on.
"These can vary depending on the amount of light and whether the area is moist, dry, hairy, or oily. And the microbiome differs with age and gender. For instance, a hormonal, sweaty teenage boy sports a very different microbiome than a sedentary, postmenopausal woman," writes physician Kara Fitzgerald, N.D.
And we see this play out in real time with real effects, says holistic and triple board-certified dermatologist Mamina Turegano, M.D., FAAD.
"Certain bacteria and fungi are just more attracted to certain body parts. For example, we know that areas that have increased sebaceous activity—face, chest, back—there are certain fungi and bacteria that like to feed on that," she explains. "One thing we see is higher rates of the acne-causing bacteria Cutibacterium acnes. It's not a pathogenic bacteria, but we know that when an environment has increased oil, it will cause the bacteria to act up and inflame the skin, causing acne. Or for fungi we see a lot of the Malassezia species, which is a yeast, and the main player in what is commonly referred to as 'fungal acne.'"
We often see this happen with several skin infections or rashes. "There are other parts of the body that are more moist, whether it be the armpits, feet, elbows, behind the knees, and nose, we see more rates of Staphylococcus bacteria Corynebacterium—both of these can cause issues when they are misbehaving," she says, noting that many of us live with Staph bacteria on our skin, but it's usually in something of a dormant state. "But if your immune system is upset—you've done something to disturb the skin, or there's a trauma—it can cause it to act up, typically in those areas."
Or also in the case of staph, researchers have even identified it to be a cause of body odor, which makes sense as to why body odor tends to concentrate around moist areas. A 2020 study found that an enzyme called C-T lyase1, released by the bacterium Staphylococcus hominis, was the cause of the pungent smell we understand to be B.O.
We also see changes with chronic conditions, like eczema. "We have found that there is a difference in the microbiome diversity: When the skin barrier is not optimal, the biome is not optimal. Not fully clear right now what's the chicken or the egg—but we do see if we restore the biome diversity with those with eczema in those patches, it helps the eczema without having to use medicine."
Your oral microbiome is also part of the discussion: "The mouth is the entrance into your whole digestive system," says functional medicine physician Frank Lipman, M.D. "The oral microbiome is really important." Some research shows that oral bacteria can actually travel toward the gut and change its microbiota2. On a more superficial level, additional research has found that the cause of halitosis, or bad breath, is actually the repercussion of a microbe imbalance. Imbalance is key here—it's not simply that "bad bacteria" was present; it was actually due to the fact that the ecosystem of the "good" and "bad" was out of whack, and they weren't able to keep each other in check.
The new & old technology of the microbiome.
For beauty fans, topical technology and cosmetic chemistry is a marvel. The sophisticated formulas we have access to, and the innovative ingredient area in them, is like nothing we've seen before. Just think about retinol, for an example. Since its development in the '70s, as a prescription acne treatment that was notoriously hard to tolerate, it has transformed into an ingredient safe for drugstore shelves and even some of the most sensitive skin among us. Thanks to developments in chemistry, researchers were able to tweak and adjust the ingredient, creating more shelf-stable and milder derivatives—without losing much of the famous efficacy. It may have taken a few decades, but the ingredient you used to have to get a doctor's note to get ahold of has become nearly ubiquitous in modern skin care culture.
Well, microbiome skin care is still in its infancy. But as we're developing new technologies and learning about the best ways to care for our barrier, we're becoming more sophisticated. It's why biome skin care is an ever-evolving category. And one area where we've seen a lot of growth, changes, and, unfortunately, misinformation.
"The microbiome is essentially an organ system and could be thought of as that important. We know that you don't want to be sterile, or without these microbes. [The problem is that] the function of the skin microbiome is far greater in scope than what we can actually understand right now. So, it is at once very difficult to say exactly how to keep the microbiome well and optimized—while also knowing it is very important to keep it healthy," physician James Hamblin, M.D., author of Clean: The New Science of Skin once told us.
Now, to start off: Some tenets of microbiome skin care are just, well, things we just happened to get right without fully understanding the why behind it. Take, for example, sulfates and harsh detergents in soaps, shampoos, and oral care. A while back, some health and skin experts started flagging that these ingredients were highly irritating to the skin, perhaps leading to skin sensitization. Turns out, they were right: Harsh sulfates have the ability to damage the microbiome and weaken the skin barrier function. "Ideal soaps are made without harsh sulfates like sodium lauryl sulfate, that can damage the skin barrier," board-certified dermatologist Whitney Bowe, M.D., tells us.
To go a step further, people also instinctively understand that certain areas of your body (or "eco-niches") require special attention as part of the hygiene process. "You can wash your armpits and groin area with soaps that have more antibacterial properties because they can handle it, whereas the rest of your body you'll typically need something gentler," says Turegano, noting to still use sulfate-free and to stick to fragrance-free in the groin area especially.
Or another example: applying lipids, oils, and butters to the skin and scalp. Humans have been practicing this for, well, ever. We've long taken soothing botanicals and turned them into body, face, and hair moisturizers because we could tell our skin barrier sometimes needed outside support to remain healthy, hydrated, and strong. We didn't fully understand, but could tell instinctively, that feeding the lipid layer helped our overall skin microbiome and barrier function.
But, one of the areas of evolving and new technology is biotic ingredients: things like pre-, pro-, and postbiotics. These are ingredients that specifically target beneficial bacteria living on the skin. This is exactly how we've come to the topical probiotic debate of late—after what seemed like a tidal wave of probiotic-infused products, researchers, dermatologists, and cosmetic chemists are skeptical of their efficacy. For good reason. It's a complicated topic but worth exploring—it affects the future of the skin microbiome, after all.
The great biotic debate.
To understand this, we must first understand the types of biome actives. Prebiotics are foods that the natural flora on our skin consumes—when you plant beneficial prebiotics on the skin, the good organisms are able to thrive. (There's a very easy comparison to your own body: When you eat better, you feel better.) Probiotics are optimal strains of living bacteria replanted on the skin, in order to balance out the natural flora (the idea being that if you can add beneficial bacteria to the skin, they'll help bring your skin to a state of calm). Postbiotics are the skin-supporting outputs from probiotics (essentially these are one of the reasons probiotics are beneficial in the first place).
Now, the majority of the biotic skin care category centers around probiotics. However, we are finding that it's not what we've been led to believe. Modern skin care products contain preservatives, which are very much needed in order to keep the formula free of pathogens, ensure stability, and guarantee shelf-life longevity. (Of course, you can and should avoid those that have been shown to be endocrine-disrupters or not eco-friendly. But there are new preservative systems used that have been shown to be effective in formulas as well as safe for skin and the environment.)
And the thing with preservatives is they do not have the ability to identify what should be living (probiotics) and what shouldn't be (harmful bacteria, mold, and so on).
"Live bacteria in skin care is overrated," says Bowe. "More so, it's not even practical to have them because anytime you're looking at a cleanser, a moisturizer, or a cream, there are preservatives in there. And there is no way to have living bacteria in that same product." Meaning when you see a probiotic topical, what you are likely seeing is actual technically para-probiotics (or nonliving bacteria) or lysates (bacterial fragments).
So instead, we turn to high-tech postbiotics. Researchers have been able to identify key beneficial outputs from the bacteria living on our skin naturally. I like to think of these as synergistic gifts, from our microbiome to our skin; our skin, in turn, becomes a more harmonious and habitable place for the bacteria. A beautiful cycle is born.
Not only were researchers able to identify these very specific outputs, but they were able to recreate them, en masse, without having to inactivate or fragment bacteria (like para-probiotics or lysates). This technological development means researchers can create targeted actives—which are able to immediately activate crosstalking with the skin directly.
For example, Lactobacillales, the "educational" bacteria of the skin. It's actually a strain of bacteria that populates our skin in our youth3 but declines as we age. In its role as educators, it teaches skin to act young, protect itself, and revitalize barrier function.
Its targeted, unique postbiotics are things like oligopeptides (even more specifically oligopeptide-5 through 13), fatty acids (including UFA, PUFA, and EFA), as well as biosurfactants, like rhamnolipids. And now, through modern technology, we are able to bioidentically recreate these natural postbiotics and infuse them into skin care. Once on the skin, they are able to crosstalk with various receptors to improve the epidermis framework regeneration, skin hydration, reduce signs of aging thanks to blocking our exposure to irritants and pollutants, stimulate microcirculation, support the skin's immune system, and calm inflammation.
Of course, we've long seen things like peptides and fatty acids in skin care. In fact, many natural creams and products contain an array of these. However, the technological advancement here is that now we're able to specifically identify what exact ones are able to work with skin receptors and act beneficially.
Essentially, we're getting closer to eliminating the guesswork—postbiotics are able to feed your skin microbiome exactly what it needs to behave optimally. And when your microbiome thrives, you do too.
This is just one of the trends mbg is predicting for 2022. Check out our full list of the latest health & wellness trends.
Alexandra Engler is the beauty director at mindbodygreen and host of the beauty podcast Clean Beauty School. Previously, she's held beauty roles at Harper's Bazaar, Marie Claire, SELF, and Cosmopolitan; her byline has appeared in Esquire, Sports Illustrated, and Allure.com. In her current role, she covers all the latest trends in the clean and natural beauty space, as well as lifestyle topics, such as travel. She received her journalism degree from Marquette University, graduating first in the department. She lives in Brooklyn, New York.