A Beneficial Diet for the Skin: Pro-, Pre-, and Postbiotics in Cosmetics
In recent years, dermatologists have increasingly highlighted the skin microbiome and its crucial role in epidermal health. "We are our bacteria," proclaims the headline of a popular article in The New York Times.
The composition of the skin microbiome varies depending on the body part: the bacteria on the scalp differ from those on the feet. The face also has its unique microbiota. Cosmetic manufacturers emphasize this by enriching creams and serums with various prebiotics and probiotics. Let's delve into the benefits of such a "diet" for the skin and whether probiotic products can help address dermatological issues.
Healthy Microbiome — Healthy Skin
Cosmetic manufacturers and beauty experts often emphasize that the skin microbiome is very sensitive and depends on numerous factors (environment, quality of food/water, cosmetics). However, the microorganisms inhabiting our skin are generally very resilient.
They endure harsh peels (though they take a long time to recover), daily makeup, hard water, and have even learned to interact with silicones in creams. Another enemy of microbes is the scorching sun: a recent study found that UV radiation destroys the cell membranes of microorganisms, leaving the skin vulnerable. Yet, the microbiota tirelessly continues its work: helping to combat oxidative stress daily, controlling inflammatory processes, and promoting wound healing.
Many studies show a connection between microbiome imbalance and chronic skin problems, such as acne, rosacea, and eczema. This is why the skin microbiome needs to be nurtured and cared for, which includes not only gentle care but also proper "nutrition." This is where cosmetics with pro-, pre-, and postbiotics come into play.
Probiotics
It seems like something for the gut? Not only! Our skin loves them too. Wise grandmothers clearly knew something about this, given the many recipes for homemade face masks with kefir and yogurt.
So, probiotics are live microorganisms that inhabit human skin. By modest estimates, about a billion of them live on one square centimeter. An impressive number, isn’t it? Naturally, such a massive gathering of microorganisms has a colossal impact on skin health.
Cosmetologists believe that just as “good” bacteria help our gut thrive, certain strains of probiotics will support skin functions. There is a basis for this: a 2015 study showed that the topical application of probiotics significantly eases the treatment of eczema, rosacea, acne, and other inflammatory processes. A publication by dermatologists from the USA confirmed probiotics' ability to support the skin’s immune response and counteract the effects of ultraviolet light. A 2016 study highlighted very promising results: probiotics were found to have an anti-aging effect.
There is one weak point with probiotic cosmetics: creating a universal formula suitable for every person’s microbiome is impossible. Even leading global experts cannot assert which strain of bacteria will suit your skin specifically or what concentration will be effective.
Which Probiotics Are Beneficial for the Skin?
The undisputed leaders in maintaining beauty are lactobacilli and bifidobacteria (Lactobacillus and Bifidobacterium in cosmetics). The former are effective in combating inflammation and enhancing the skin's protective functions. A study by American scientists found that lactobacilli help the skin produce antimicrobial peptides, strengthening its antimicrobial barrier.
Bifidobacteria help the microbiome function correctly. Several studies have confirmed that strains of these bacteria help reduce transepidermal water loss and decrease sensitivity symptoms.
An important nuance: biotic formulas are not well-studied in terms of interaction with other active components. Therefore, it is better not to combine them with acidic formulas (though they can be used to restore the skin after an unsuccessful peel), retinol, and peptides.
Prebiotics
To simplify complex chemical terminology, prebiotics can be described as beneficial food for probiotics. They create a proper nutrient environment where good bacteria thrive and multiply. When probiotics have something to feed on, the skin microbiome flourishes, enhancing its activity and strengthening the protective barrier.
Which Prebiotics Are Beneficial for the Skin?
Over the past two to three years, the beauty industry has significantly expanded the list of prebiotics found in cosmetics.
- Plant polysaccharides: Xylitol, rhamnose, arabinogalactan, fructooligosaccharides (reduce sensitivity, enhance skin's protective function, reduce transepidermal water loss)
- Glucomannan (dietary fiber extracted from the Amorphophallus konjac plant, rich in vitamins)
- Microalgae (reduce pigmentation, moisturize the skin, and protect it from UV radiation)
- Magnesium (regulates sebum production, combats chronic breakouts)
Postbiotics
Live bacteria are not the most stable material for making cosmetic products. Probiotics are sensitive to temperature fluctuations, do not get along with most preservatives, and significantly reduce the product's shelf life. Therefore, in recent years, postbiotics have gained particular popularity. This is a separate group of prebiotics that includes bacterial by-products or their remains, known as lysates. Cosmetic manufacturers focus on them because they have the same activity as probiotics but are more stable and easier to control in formula formulation.
Which Postbiotics Are Beneficial for the Skin
Since these substances are derived from the by-products of fermented bacteria, they will be listed on the label as "lactobacillus ferment" or "bifidobacterium lysate." In general, it is advisable to look for cosmetics with fermented components — the concentration of flavonoids, polyphenols, and vitamins in fermented extracts is higher than in fresh ones.