by The Cosmetic Chemist Staff
September 15, 2016
There are many beneficial effects of probiotics for human health and well being. Numerous studies demonstrate that consumption of foods containing probiotics can help avoid intestinal inflammatory diseases, regulate cholesterol and insulin, reduce the risk of colon cancer, and increase the absorption of calcium.
Probiotics are live microbial species that are found in certain foods, and they should be differentiated from prebiotics, which are non-digestable food ingredients that promote the growth of microbiota.1 Synbiotics, on the other hand, are products that contain both probiotics and prebiotics.
Essentially, probiotics (and prebiotics) help maintain homeostasis of microflora in the gastrointestinal tract. Inasmuch, they prevent colonization by pathogenic or unwanted microbes.
Typical foods that contain probiotics consist of yogurt, kefir, sourdough bread, miso, tempeh, sauerkraut (non-pasteurized), kimchi, and pickles (in brine, not vinegar). As an example, yogurt contains the probiotic bacteria, Lactobacillus acidophilus, which provides it with its beneficial properties for gastrointestinal health.
In comparison to the skin, the gastrointestinal ecosystem is more complex, containing a rich diversity of microflora. More than likely, the harsh environment of the skin prevents many microorganisms from inhabiting its surface. Nevertheless, the microbiota of the skin plays an important role in maintaining homeostasis.
The skin contains resident and transient microbial species. The most common resident species consist of Propionibacteria (P. acnes, P. avidum, and P. granulosum), Coagulase-negative Staphylococci (Staphylococcus epidermis), Micrococci, Corynebacteria, and Acinetobacter. Some of the transient species consist of Staphylococcus aureus, Escherichia coli, Pseudomonas aeroguinosa, and Bacillus species.2 Resident species are able to establish colonies on the skin and reproduce, thereby providing a beneficial environment, while transient refers mostly to non-beneficial bacteria that are not able to establish colonies on the skin surface.
In 1930, Stokes and Pillsbury hypothesized a connection between the emotional or stress state of an individual and gastrointestinal health, which in turn influence the health state of skin.3 Their findings and theories were way ahead of their time, and recent insights provide persuasive evidence of the relationship between these three regions of the anatomy.4-5
There is also a significant amount of evidence in the literature demonstrating that probiotics are efficacious in the prevention of atopic dermatitis, especially in children during the pre- and post-natal periods.6 However, evidence that probiotics are efficacious in the treatment of existing atopic dermatitis is still controversial, and further study is warranted.7 While currently not accepted as common deramatological practice in a clinical setting, there are also studies demonstrating positive results in the treatment of eczema, acne vulgaris, wound healing, and photoprotection with probiotics.4,7 While these results are promising, there is a need to conduct further large scale studies before such treatment modalities are adopted into clinical practice.8
In the realm of cosmetic treatments, a slightly different strategy to fortifying the skin’s microbiota is accomplished by topical treatment. There are a number of products available in the market place, most in the form of skin care creams, that are often classified as probiotic skin care. While the majority of studies on the beneficial effects of probiotics on skin health have been conducted by the oral administration route, there is increasing evidence that topical application is also a viable treatment modality.9-11 Future studies should help elucidate differences in the efficacy of topical and oral administration of probiotics.
While the precise mechanism of probiotic action on the skin is not known, it has been suggested that probiotics may form a protective barrier, which prevents skin cells from detecting overlaying malicious microbes (known as bacterial interference). Such an occurrence could impede the communication of keratinocytes and Langerhans cells with immune system thereby circumventing an immune response.12 It has also been noted that probiotics have antimicrobial properties and could be used as alternatives to conventional therapies, such as antibiotics.2 Furthermore, the immunomodulating effects of probiotics—more than likely through their influence on the immune response signaling behavior of keratinocytes—help reduce immune reactions that normally result in inflammation, redness, and irritation.13
References
1. P. Gourbeyre, S. Denery, and M. Bodinier, Probiotics, prebiotics, and synbiotics: impact on the gut immune system and allergic reactions, J. Leukoc. Biol., 89, 685-695 (2011); doi: 10.1189/jlb.1109753. Epub 2011 Jan 13.
2. J. Krutmann, Pre- and probiotics for human skin, J. Dermatol. Sci., 54, 1-5 (2009).
3. J.H. Stokes and D.M. Pillsbury, The effect on the skin of emotional and nervous states. III. Theoretical and practical consideration of a gastro-intestinal mechanism, Arch. Derm. Syphilol., 22, 962-993 (1930).
4. W.P. Bowe and A.C. Logan, Acne vulgaris, probiotics and the gut-brain-skin axis – back to the future?, Gut Pathogens, 3, 1-11 (2011).
5. W. Bowe, N.B. Patel, and A.C. Logan, Acne vulgaris, probiotics and the gut-brain-skin axis: from anecdote to translational medicine, Benef. Microbes, 5, 185-189 (2014).
6. V. Fuchs-Tarlovsky, M.F. Marquez-Barba, and K. Sriram, Probiotics in dermatologic practice, Nutrition, 32, 289-295 (2016).
7. K.L. Baquerizo Nole, E. Yim, and J.E. Keri, Probiotics and prebiotics in dermatology, J. Am. Acad. Dermatol., 71, 814-821 (2014).
8. S. Kumar, B.B. Mahajan, and N. Kamra, Future perspective of probiotics in dermatology: an old wine in new bottle, Dermatol. Online J., 20(9), Sep. 16 (2014).
9. A. Guéniche, K. Dahel, P. Bastien, R. Martin, J.F. Nicolas, and L. Breton, Vitreoscilla filiformis bacterial extract to improve the efficacy of emollient used in atopic dermatitis symptoms, J. Eur. Acad. Dermatol. Venereol., 22, 746-747 (2008).
10. L. Di Marzio, B. Cinque, F. Cupelli, C. De Simone, M.G. Cifone and, M. Giuliani, Increase of skin-ceramide levels in aged subjects following a short-term topical application of bacterial sphingomyelinase from Streptococcus thermophilus, Int. J. Immunopathol. Pharmacol., 21, 137-143 (2008).
11. H.F. Huseini, G. Rahimzadeh, M.R. Fazeli, M. Mehrazma, and M. Salehi, Evaluation of wound healing activities of kefir products, Burns, 38, 719-723 (2012).
12. W.P. Bowe, Interview with the American Academy of Dermatology, Could probiotics be the next big thing in acne and rosacea treatments, Schaumburg, IL, U.S:, Feb. 3, 2014; www.aad.org.
13. M.M. Kober and W.P. Bowe, The effect of probiotics on immune regulation, acne, and photoaging, Int. J. Womens Dermatol., 1, 85-89 (2015).