Can skin care products balance the vitally important good and bad bacteria living on your skin’s surface? In other words, can you balance your skin’s microbiome to keep skin healthy and normal? In the world of science, the facts say yes, to some extent, but not by merely applying probiotics.
Balancing Your Skin’s Microbiome
Probiotics are essential for your body’s overall health but the concept of probiotics for maintaining healthy, younger-looking skin is a relatively new concept. This is a crash course on one of the more complicated subjects in skin care, but hang in there, I’ll get you through it.
The microbiome of the body and skin are fascinating areas of study with massive amounts of research and new assessments coming to light on a regular basis. When it comes to skin and probiotics, there is still a lot we don’t know but there is also a lot we do know. And the research isn’t just about probiotics, it’s about prebiotics and postbiotics too. Understanding how the pieces of the microbiome puzzle fit together will help you take care of your skin and not waste money on products that can’t help.
Pre-, Pro-, and Postbiotics
Your skin’s microbiome is made up of “good” and “bad” microbes that live on the surface of skin. Probiotics are the living microbes (bacteria and yeast) that exist on skin. Prebiotics are the substances on skin that help feed and encourage the growth and balance of probiotics. Postbiotics are the substances probiotics generate which are fundamental to healthy skin.
The topic of pre-, pro-, and postbiotics for skin care could be summed up by asking how “dirty” does your need skin to be? After all, when you think of bacteria and yeast living on your skin, that certainly doesn’t sound clean. Most people would reach for a disinfectant! But in order to help support the fight against signs of aging, acne, inflammation, some skin disorders, environmental damage, dehydration, or strengthen the surface of skin, the skin needs to be pretty darn dirty. A disinfectant would actually destabilize your microbiome. The goal is to have a balanced thriving, microbiome. How to go about being appropriately “dirty” is where skin care can help. But first you need to understand what is meant by “dirty,” as that will help you grasp the role of pre-pro-, and postbiotics for skin.
In science, the basic terms involving probiotics are microbiota and microbiome. The microbiota refers to all the living microorganisms existing on skin or in the body. The term “microbiome” refers to the genetic composition of all those microorganisms (microbes). The genetic composition of these microbes is considered to be as significant and daunting a decoding project as mapping the human genome was. For the purposes of this article we will use the more popular term “microbiome” to describe what is happening and what is most beneficial for your skin.
The human body’s microbiome consists of trillions (yes, trillions) of living microbes and their genetic components that live on skin. These microbes include good and bad bacteria, viruses (yes, viruses), yeasts, and an incalculable number of other microorganisms. It is estimated that a single square centimeter of human skin can contain a billion microbes and their components.
Strangely enough, our bodies are dependent on the healthy balance of all these trillions of microbes. Our skin’s microbiome also needs to be in balance to maintain health, normal function, and protection.
Aside from trying to grasp the scope of trillions of microbes comprising the body’s microbiome, what is even more unmanageable is that no two people have the same microbiome in their body or on their skin. Everyone’s microbiome is different. And your own microbiome changes based on the time of day, the weather, your health, your geographic location, among other factors such as sun damage or using skin care products that cause irritation.
Adding to the intricacy is that skin’s microbiome varies in different parts of the body and it even varies in different parts of the same area. For example your chin area may not have the same microbiome as your nose or forehead. This is one seriously nuanced area of science!
How Probiotics Work on Skin
Skin begins creating its microbiome at birth. It continues to grow and change as we age and then stabilizes in adulthood. What makes the skin’s microbiome unstable is almost always some type of inflammation. Whether internal (skin disorders, pH imbalance, disease) or external (pollution, sun damage, irritating or abrasive skin care products), inflammation is a big problem.
When the microbiome is stable and balanced, all the microbes living on the skin and in the pores and sweat glands, digest (literally eat) some of the skin’s content of oils, fatty acids, proteins, and dead skin cells. After the microbes are done eating, they produce vital substances called postbiotics. Skin needs these postbiotics to be healthy and to prevent or reduce skin problems.
What is meant by having a healthy or balanced microbiome? Some of the microbes on skin are helpful while some are (or can become) harmful. The good microbes are often referred to as “resident bacteria,” while the bad microbes are called “transient bacteria.” Oddly enough, when the skin’s microbiome is out of balance, the good microbes can become bad and the bad ones can become good (we know, confusing, but facts are facts). This means a balanced microbiome must have the good and the bad to keep everything in harmony. It’s not as simple as getting rid of all the bad bacteria so the good can flourish; doing so would have the opposite effect and not be good for skin!
When the skin’s microbiome is balanced, and the good and bad microorganisms are working together, postbiotics are created. Postbiotics include peptides, proteins, amino acids, enzymes, hyaluronic acid, lactic acid, ceramides, antioxidants, and other vitally important substances for skin. Isn’t that amazing? These postbiotic substances the probiotics naturally generate do the following (more about this at the end of this article):
- Strengthen the skin’s surface to protect against environmental damage.
- Enhance skin’s ability to become (and stay) properly hydrated.
- Diminish factors that trigger sensitized, reddened skin.
- Restore and maintain a healthy pH balance on skin’s surface.
What Causes Your Skin’s Microbiome to Become Unbalanced?
So many things can impact your skin’s microbiome and they are exactly what damages skin in other ways too. What we know for certain is anything that causes skin inflammation throws the microbiome into a state of confusion that can become a vicious cycle. It isn’t easy to get it back in balance. Everything from sun damage, irritating or abrasive skin care products, an unhealthy diet, smoking, hormonal skin disorders, immune-related skin disorders, wounds, and illness can block the microbiome’s efforts to stay balanced.
It’s interesting to point out that active Ingredients like retinoids, niacinamide, sunscreen ingredients, AHAs, BHA, and benzoyl peroxide among others do not disturb the skin’s microbiome. This is because all these ingredients either have anti-inflammatory properties or they are naturally acidic. Anything that reduces inflammation helps stabilize the microbiome and because the skin’s pH is acidic (AHAs and BHA are acidic) they end up all being helpful.
Can Applying Probiotics to Skin Balance its Microbiome?
No, it’s not possible. The problem is one of sheer numbers. There are billions of us in the world and each of us has a different, ever-changing microbiome. In short, there’s nothing consistent about the skin’s microbiome so there’s no way any product or supplement can truly balance it.
Looking at it another way, even if everyone had the exact same microbiome, how would any skin care product know which trillions of microbes on your skin were out of balance? And given “bad” biotics are as important as “good” biotics, it would be unconscionable to ever formulate a skin care product containing Staphylococcus or Streptococcus bacteria. Yet even those infectious bacteria are a natural part of everyone’s microbiome!
Another serious limitation for probiotics in skin care products to balance the microbiome is the fact that the microbiome needs living bacteria, viruses, yeast and fungus, and other microorganisms (the good and the bad) to function as it should. But because skin care products are formulated with preservatives to prevent mold and bad bacteria from growing out of control in the product, a responsible formula would kill the live probiotics it contained.
Claims around balancing skin’s microbiome are really about what PREbiotics and POSTbiotics can do for skin, not about what PRObiotics can do.
Can Applying Probiotics to Skin Offer Any Benefits?
Research has looked at numerous probiotic and probiotic-derived ingredients for skin and some have shown distinct benefit for reducing inflammation and some skin disorders, particularly acne and eczema.
The problem is that not all research agrees with this. Also, the various studies haven’t looked at the same probiotic. Another issue is the studies were either done on animals or in a laboratory, not on people. Some studies were not done with a placebo control (meaning one product with the probiotic was applied on one person and the other person applied a product that didn’t contain it), or were not done blinded (meaning the researcher didn’t know who was getting which treatment). These are big limitations to making valid conclusions about which probiotics can be beneficial.
Having said that, what agreement does exist is for a handful of probiotics and probiotic derivatives (often referred to as “lysates”) that can have benefit for skin when applied topically. This is due to their stability and ability to reduce inflammation on skin. Proven probiotics include the species Lactobacilli, Acidophilus, and Bifidobacteria bifidum.
What About Applying Prebiotics to Skin?
Skin care products containing prebiotics are a far better way to establish a healthy microbiome. That’s because when you apply products containing prebiotics they help your skin make its own probiotics it needs. That way your skin is better able to reinforce its microbiome’s natural balance.
Prebiotics for skin are carbohydrate-based, often in the form of sugars. Plant extracts with prebiotics that can be included in skin care products include oats, barley, wheat bran, asparagus, onion, banana, and a plant fiber known as inulin, found in chicory root. Even better for skin when applied topically are prebiotic plant sugars, such as xylitol, rhamnose, and a large group of ingredients known as fructooligosaccharides, which are potent sources of prebiotics (not to mention being natural hydrators) and therefore have inherent capacity to help generate probiotics.
To sum it up: you cannot simply balance your skin’s microbiome — have you noticed, there is nothing simple about this topic?! However, prebiotics work beautifully as an energy source to help skin make the probiotics it needs.
What About Postbiotics?
When the microbiome is balanced (at least for as long as it can be) the probiotics living on skin produce important substances. These great substances are referred to as postbiotics which include peptides, hyaluronic acid, lactic acid, ceramides, and antioxidants. Together these postbiotics assist in keeping skin hydrated, strengthened, and protected from the environment. They also reduce redness, diminish acne, and improve other skin disorders where inflammation is the trigger.
However, because you can never really tell if your microbiome is or isn’t balanced and because of pollution, sun damage, and skin disorders, you can safely assume it is generally out of balance. Then giving your skin the substances a healthy microbiome would make on its own from other skin care products that contain them is great for your skin. But it is still very helpful to do what you can to keep your microbiome as balanced as possible. The best way to do that is to use a product that contains a mix of prebiotics, probiotics, and postbiotics in a cream, lotion, or serum (it’s up to you which texture you prefer).
References* used for this article:
American Journal of Clinical Dermatology, January 2019, pages 1-10.
Archives of Dermatologic Research, April 2018, pages 181-185 and August 2017, pages 411-421.
Journal of Investigative Dermatology, March 2017, pages 561-568
Journal of the European Academy of Dermatology and Venereology, December 2016, pages 2038-2047.
Australasian Journal of Dermatology, November 2015, pages 268-274.
*Free access is available for some of the above published research but not for all. Many scientific journals and/or publications I use require subscriptions or I have to purchase the individual study. Due to copyright laws and terms of service agreements I cannot share access to the journals or studies that require purchase.