Could bacteria be the secret key to beautiful skin? Current scientific research suggests this may be the case! Many of us are familiar with the concept that we need to have a hearty population of beneficial bacteria in our intestines in order to promote optimal digestive health. Beneficial bacteria perform numerous important functions in the gut; they assist with the breakdown of food, the metabolism of toxins, and maintain the integrity of the walls of the digestive tract.

In order to support beneficial bacteria in the gut, many of us eat probiotic foods such as sauerkraut, kimchi, yoghurt, and kefir. There are also a wide variety of encapsulated probiotic supplements available for us to choose from at grocery stores and health food stores. While a great deal of emphasis has been placed on the digestive benefits of probiotics, it turns out that the importance of the bacteria living in our bodies – collectively referred to as our “microbiome” – extends far beyond the digestive tract, all the way to our skin!

Amazingly, the population of beneficial bacteria in our guts has the ability to influence the health and appearance of our skin! Eating probiotic foods and taking probiotic supplements can help support those beneficial bacteria, and start us on the path towards achieving radiant skin. I first learned about the connection between probiotics and skin health several years ago, when I decided that I was tired of living with acne and wanted to find a natural solution to my skin troubles. My own experience in replenishing the beneficial bacteria in my body with probiotics has not only healed my acne but has given me skin that I am proud to live in!

There is a fascinating body of scientific research demonstrating the interaction between probiotics and skin health. ¹ Amongst scientists, the connection between the skin and digestive tract has been termed the “gut-skin axis.” In regards to the gut-skin axis, scientists have found that the beneficial bacteria living in our intestines first affect the local environment of the gut, and then proceed to influence systemic bodily processes, which in turn affects skin health. Beneficial bacteria in the gut form a strong foundation for overall health by strengthening the walls of the intestine, which are often referred to as the “intestinal barrier.” When the intestinal barrier is weak, substances such as undigested food proteins and toxins are able to escape between cells of the intestine into the rest of the body. This undesirable process is referred to as “leaky gut.” Leaky gut creates inflammation throughout the body, including in the skin. An intestinal barrier that has been strengthened by probiotics prevents leaky gut from occurring, and can, therefore, prevent inflammation from developing throughout the body and in the skin. Inflammation is a major cause of skin woes, so anything we can do to prevent inflammation will help improve skin health!

In addition, when the intestinal barrier is strong thanks to beneficial bacteria and regular probiotic consumption, absorption of nutrients from food is also improved. These nutrients keep hormones balanced, including hormones that regulate blood sugar levels. Blood sugar regulation has a great impact on skin health, especially in the case of acne. Optimal nutrient absorption also provides cells with the fuel they need to thrive, including the cells composing your skin. As you can see, a healthy gut really is essential for creating healthy skin! An imbalance in beneficial bacteria in the gut, along with an inadequate intake of probiotics, can, therefore, have major impacts on the health of your skin. The beneficial bacteria residing in your gut, in fermented foods, and in probiotic supplements may be tiny, but don’t underestimate their amazing power to affect your body’s largest organ, your skin!

Probiotics and skin health research

Within the past few years, a number of scientific studies have examined the effects of probiotics on skin health. Probiotics taken internally and applied topically may improve signs of skin ageing, eczema, acne, and rosacea. Here is some of the most recent research on probiotics for skin health:

Skin ageing

A type of probiotic called Lactobacillus plantarum has been found to reduce signs of skin ageing including loss of skin elasticity, decreased hydration, depth of wrinkles, and “skin gloss,” referring to the luminance of the skin. These findings suggest that L. plantarum may be an effective nutricosmetic agent or a nutritional product that offers cosmetic benefits. ² Lactobacillus plantarum is widely available in probiotic supplements. Fermented foods such as yoghurt, sauerkraut, kombucha, and kimchi are also rich sources of lactobacilli probiotics, including Lactobacillus plantarum.

Interestingly, the skin is designed to have a slightly acidic pH of 4.2-5.6; this helps prevent overactivity of enzymes that break down and age skin, such as proteases. Probiotics such as Lactobacilli produce acidic molecules that lower the pH of the skin, which can lower protease activity levels and help the skin maintain a healthy, youthful quality. ³

Another type of probiotic that may improve signs of skin ageing is Bacillus coagulans. This bacterium produces antioxidants that scavenge free radicals in the body. Excessive free radical damage can lead to skin ageing, so by “mopping up” these damaging substances, ingestion of Bacillus coagulans may reduce signs of skin ageing. ³ Bacillus coagulans is most readily obtained in the form of a supplement; it is hard to quantify its presence in foods.

Atopic dermatitis

Atopic dermatitis, an itchy inflammation of the skin that often involves dry, scaly patches, may respond beneficially to the probiotic Lactobacillus acidophilus. ⁴ In a group of 49 Japanese adults with atopic dermatitis, ingestion of Lactobacillus acidophilus for 8 weeks led to a significant decrease in harmful immune activity and bodily inflammation. Lactobacillus salivarius is another probiotic that may both prevent and help reverse atopic dermatitis in adults. In 38 adult patients with moderate to severe atopic dermatitis, L. salivarius demonstrated immunomodulatory properties, decreased populations of staphylococci (a type of “bad” bacteria) in the body, and significantly decreased atopic dermatitis symptoms in the adults. ⁵

Probiotics may also be useful for treating atopic dermatitis in infants and children. The ingestion of probiotic species Bifidobacteria bifidum, Bifidobacteria lactis, and Lactobacillus acidophilus by pregnant women appears to reduce the incidence of atopic dermatitis in their infants during the first year of life. ⁶ In addition to being administered in the prenatal period, Lactobacilli and Bifidobacteria probiotics given to infants in the postnatal period reduces the incidence of atopic dermatitis. ⁷ This is exciting news, as many children today, unfortunately, suffer from allergic skin conditions. Probiotics appear to be a safe, effective way to not only prevent but reverse, allergic skin conditions such as atopic dermatitis.

Acne

There is hope for those dealing with adult acne! It appears that a probiotic called Lactobacillus rhamnosus can improve cases of adult acne. It does this by normalising the expression of certain genes that are involved in insulin signalling. ⁸ High insulin leads to increased sebum production, which is the oily secretion made by sebaceous glands in the skin. Increased sebum production can congest pores in the skin and lead to acne. By mediating insulin levels, and thus sebum production, it may be possible to reverse adult acne and achieve clear, beautiful skin! Lactobacillus rhamnosus may be found in foods, but for a concentrated dose, it is best to take it in the form of a probiotic.

The anti-inflammatory actions of probiotics may also help reduce acne. In a study of 45 adult females, administration of probiotics along with an antibiotic led to a significant decrease in acne lesions, when compared to a control group that only received an antibiotic. ⁹

 Another probiotic called Lactobacillus reuteri has been found to reduce perifollicular inflammation, which is one of the first steps in the acne process. ³ Lactobacillus reuteri can be found both in fermented foods and in probiotic supplements.

Rosacea

Probiotics also hold promise in the treatment of rosacea, a condition in which facial blood vessels enlarge and small bumps appear, lending the skin a rough red appearance. In 2013, the American Academy of Dermatology proposed the use of probiotics in the treatment of rosacea.¹⁰ Interestingly, an overgrowth of bacteria in the small intestine, called Small Intestinal Bacterial Overgrowth (SIBO), has been found to be ten times more prevalent in those with rosacea than in healthy controls. The administration of oral probiotic supplements has been shown to improve SIBO, and correction of SIBO has, in turn, been shown to reduce rosacea. It appears that perhaps an imbalance in the microbiome is the root cause (or one of the root causes of rosacea), and by correcting that cause, rosacea may be reversed. ¹¹ Increasing one’s intake of probiotic foods such as yoghurt, kefir, and kimchi may help rebalance the gut microbiome, crowding out any “bad” bacteria that may be contributing to SIBO. Implementing a broad-spectrum probiotic supplement could also potentially be helpful.

Topical probiotics

While up until now, I have referenced probiotics as being available largely through foods or supplements, another class of probiotics is currently emerging in the natural health scene – topical probiotics. Topical probiotics are probiotics administered through mediums such as creams and lotions. These products show therapeutic promise for a variety of skin ailments, as our skin also hosts its own special microbiome that must be cared for in order for it to stay healthy. The skin microbiome can be disrupted by the use of chemical-laden body care products, as well as by antibiotics. Using natural body care products that don’t strip the skin of its normal oils may help prevent imbalances in the skin microbiome. However, applying probiotics to the skin may offer very unique benefits in terms of improving skin health and appearance.

The first mention of topical probiotics as a therapeutic treatment for skin conditions appeared in medical literature in 1912, and was termed “topical bacteriotherapy.” It was not until 1999 that researchers were able to hone in on exactly how probiotic application to the skin might improve dermatological health. They found that Streptococcus thermophilus, a species of probiotic typically found in yoghurt, increased ceramide production in keratinocytes, the cells that create our skin. Increased ceramide production strengthens the lipid barrier of the skin and makes it more resistant to dryness. ¹² Streptococcus thermophiles may, therefore, help to reverse dry skin conditions. Further research has indicated that topical Bifidobacterium longum and Lactobacillus paracasei can reduce skin inflammation by mediating the activity of substance P, a polypeptide released by nerves and immune cells that induce inflammation in the body and also promotes sebum production. ¹³ The topical probiotics used in both of these studies were laboratory-produced creations, but beauty companies are beginning to hop on board the topical probiotic train, making retail versions similar to the studied topical probiotics.

While more research is needed in this area, topical probiotics definitely show therapeutic promise in the promotion of skin health! If you are not ready to shell out money for a topical probiotic cream, consider trying a DIY probiotic beauty trick – purchase some organic yoghurt at the grocery store, and apply it at home as a face mask! A yoghurt mask can do wonders for exfoliating the skin and promoting a radiant glow!

Conclusion

The human microbiomes both in the digestive tract and on the skin are intrinsically linked with dermatological health. A healthy gut serves as a strong foundation for health and can influence a variety of bodily processes including systemic inflammation, oxidative stress, blood sugar control, and cellular lipid production. These processes, in turn, affect the health of the skin. Probiotics taken both internally through foods and supplements and applied externally as topical probiotics, appear to be a promising and safe therapeutic modality for various skin conditions. A strong body of scientific research indicates that probiotics may improve signs of skin ageing, eczema, acne, and rosacea.  By restoring the microbiomes of the skin and intestines with probiotics, it may be possible to reverse skin disorders and achieve healthy, beautiful skin!

References and Sources:

1. Bowe, W.P. and Logan, A.C. (2011). Acne vulgaris, probiotics and the gut-brain-skin axis – back to the future? Gut Pathogens, 3:1. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3038963/.
2. Lee, D.E., Huh, C.S., Ra, J., Choi, I.D., Jeong, J.W., Kim, S.H., Ryu, J.H., Seo, Y.K., Koh, J.S., Lee, J.H., Sim, J.H., Ahn, Y.T. (2015). Clinical evidence of effects of Lactobacillus plantarum HY7714 on skin ageing: A randomized, double blind, placebo-controlled study. Journal of Microbiology and Biotechnology, 25(12), 2160-2168. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/26428734.
3. Kober, M.M. and Bowe, W.P. (2015). The effect of probiotics on immune regulation, acne, and photoageing. International Journal of Women’s Dermatology, 1(2): 85-89. Retrieved from https://www.sciencedirect.com/science/article/pii/S2352647515000155.
4. Inoue, Y., Kambara, T., Murata, N., Komori-Yamaguchi, J., Matsukura, S., Takahashi, Y., Ikezawa, Z., Aihara, M. (2014). Effects of oral administration of lactobacillus acidophilus L-92 on the symptoms and serum of atopic dermatitis in Japanese adults: A double-blind, randomized, clinical trial. International Archives of Allergy and Immunology, 165, 247-254. Retrieved from https://www.karger.com/Article/Abstract/369806.
5. Drago, L., Toscano, M., De Vecchi, E., Piconi, S., Iemoli, E. (2012). Changing of fecal flora and clinical effect of L. salivarius LS01 in adults with atopic dermatitis. Journal of Clinical Gastroenterology, 46 Suppl, S56-S63. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/22955359.
6. Kim, J.Y., Kwon, J.H., Ahn, S.H., Lee, S.I., Han, Y.S., Choi, Y.O., Lee, S.Y., Ahn, K.M., Ji, G.E. (2010). Effect of probiotic mix (Bifidobacterium bifidum, Bifidobacterium lactis, Lactobacillus acidophilus) in the primary prevention of eczema: a double-blind, randomized, placebo-controlled trial. Pediatric Allergy and Immunology, 21(2 Pt 2), e386-393. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/19840300.
7. Panduru, M., Panduru, N.M., Salavastru, C.M., Tiplica, G.S. (2015). Probiotics and primary prevention of atopic dermatitis: a meta-analysis of randomized controlled studies. Journal of the European Academy of Dermatology and Venereology, 29 (2015), 232–242. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/24698503.
8. Fabbrocini, G., Bertona, M., Picazo, Ó., Pareja-Galeano, H., Monfrecola, G., Emanuele, E. (2016). Supplementation with Lactobacillus rhamnosus SP1 normalises skin expression of genes implicated in insulin signalling and improves adult acne. Beneficial Microbes, 6, 1-6. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/27596801.
9. Jung, G.W., Tse, J.E., Guiha, I., Rao, J. (2013). Prospective, randomized, open-label trial comparing the safety, efficacy, and tolerability of an acne treatment regimen with and without a probiotic supplement and minocycline in subjects with mild to moderate acne. Journal of Cutaneous Medicine and Surgery, 17, 114-122. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/23582165.
10. Vemuri, R.C., Gundamaraju, R., Sekaran, S.D., and Manikam, R. (2015). Major pathophysiological correlations of rosacea: A complete clinical appraisal. International Journal of Medical Sciences, 12(5), 387-396. Retrieved from https://www.medsci.org/v12p0387.pdf.
11. Parodi, A., Paolino, S., Greco, A., Drago, F., Mansi, C., Rebora, A., Parodi, A., Savarino, V. (2008). Small intestinal bacterial overgrowth in rosacea: clinical effectiveness of its eradication. Clinical Gastroenterology and Hepatology, 6(7), 759-764. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/18456568.
12. Di Marzio, L., Cinque, B., De Simone, C., Cifone, M.G. (1999). Effect of the lactic acid bacterium Streptococcus thermophilus on ceramide levels in human keratinocytes in vitro and stratum corneum in vivo. Journal of Investigative Dermatology, 113(1), 98-106. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/10417626.
13. Lee, W.J., Jung, H.D., Lee, H.J., Kim, B.S., Lee, S.J., Kim, D.W. (2008). Influence of substance-P on cultured sebocytes. Archives of Dermatological Research, 300(6), 311-316. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/18427822.

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