During the past few years, the probiotic supplement market has experienced an astounding amount of growth due to the now well-known health benefits of the "good bacteria." Now, the tiny-but-mighty microorganisms are making their way into our cosmetic products. The evidence collected so far has shown promising results in the treatment of several inflammatory conditions of the skin, so we may expect to find them in a growing number of beauty products, including skin care and makeup products. But, before you rush to spread kefir on your face, you should read more about the role of bacteria on your skin and why probiotics can be so beneficial.
Our Skin is Covered in Bacteria
As scary as it may sound, our skin is covered in microorganisms that under normal conditions (when the skin is healthy) live in harmony. They are called the skin microbiome. Most of these organisms are completely harmless or even beneficial to the skin. However, under certain circumstances, which include environmental factors, use of antibiotics, and certain cosmetic products, the skin microbiome can become compromised. Pathogens (harmful organisms) may grow and cause inflammation. Inflammatory conditions of the skin, such as acne, dermatitis, psoriasis and even skin cancer, may develop or worsen.
The Skin Barrier
The skin barrier (also known as the acid mantle, which has a protective function against environmental aggressors) is located in the outer layer of the skin. In order for the barrier to function properly and effectively to protect the skin from harmful organisms, the pH of the skin has to be slightly acidic (between 4.5 and 6.5). When the pH becomes too acidic or too alkaline, the barrier function is compromised and pathogens can grow, leading to the inflammatory conditions mentioned above.
One factor that can influence the skin's pH is sebum production — what we typically call oil. Oily skin types tend to have a more acidic pH, while dry skin types tend to have a higher, more alkaline pH. Topical probiotics may also help to reduce the skin's pH, discouraging the growth of pathogens and favoring the growth of the resident (beneficial) bacteria.
What Can Topical Probiotics Do for Your Skin?
In patients with certain inflammatory skin conditions, such as acne and rosacea, topical probiotics can form a protective shield preventing pathogens on the skin from provoking an immune reaction. Topical probiotics may also have antibacterial properties that can kill harmful bacteria and prevent the inflammation from occurring.
If you have acne...
A few studies have shown that topical probiotics can be very beneficial for acne sufferers. One study concluded that topical application of a certain strain of probiotics may improve lesions and repair the skin barrier in patients with acne. While more research is needed, evidence from another study suggested that topical probiotics may be even used as alternative treatment to topical antibiotics in patients with acne.
If you have sensitive skin or rosacea...
Topical probiotics have shown beneficial activity in sensitive and dry skin types. A specific strain of bacteria (S. Thermophiles) that was used in a study effectively improved the skin barrier and helped to improve hydration levels.
If you're looking to for anti-aging benefits...
By preventing inflammation from occurring and by building collagen, topical probiotics may also prevent premature aging.
While more research is needed to determine how topical probiotics can benefit the skin, the results have so far been very promising. The challenge that researchers are currently facing is finding out which bacteria strains and in what form (live bacteria is generally not preferred by formulators, in favor of prebiotics and bacterial cell lysates) can be more effective for each skin condition.
It may not be a bad idea to do a yogurt face mask after all.