Lactobacillus reuteri DSM 17938 – A Comparative Study on the Effect of Probiotics and Lysates on Human Skin

Ia Khmaladze, Éile Butler, Susanne Fabre, Johanna M Gillbro Experimental Dermatology, 2019 Jul;28(7):822–828, DOI: 10.1111/exd.13950, PMID: 31021014.

Randomized clinical study | Double-blind | Split-face | Uppsala University

The skin's microbiome can play an important role in maintaining skin health and potentially preventing premature aging. The use of probiotics in skincare applications is attractive as it can offer an alternative for inflammatory skin conditions, as well as dry or sensitive skin.

For the first time, a comparative study of live bacteria versus lysate of the probiotic strain L. reuteri DSM 17938 will be conducted for topical application on skin, focusing on anti-inflammatory effect, skin barrier function, and antimicrobial activity.

Ex vivo skin models: reconstructed human epidermis (RHE) and native human skin explants. UVB-induced inflammation model. In vitro assays for antimicrobial activity against skin pathogens.

Both live bacteria and lysate reduced proinflammatory IL-6 and IL-8 in UVB-induced inflammation. Live L. reuteri DSM 17938 significantly increased aquaporin-3 (AQP3) gene expression, which improves the skin barrier's moisture transport.
Live bacteria exhibited antimicrobial activity against S. aureus, S. pyogenes M1, C. acnes AS12, and P. aeruginosa – effects completely lacking in the lysate.

L. reuteri DSM 17938 may be beneficial for general skin health, preventing UVB-mediated inflammation and photoaging, improving barrier function, and assisting with skin conditions with an inflammatory tendency – thanks to its antimicrobial, anti-inflammatory, and barrier-strengthening properties. The study shows that live bacteria are superior to lysates for several of these effects.

Figure 1 shows a reduction in skin irregularities in the eye area after 1 month of using Probiotic Concentrate.

Figure 2 shows a reduction in pore size and number of pores in the forehead after 1 month of using Probiotic Concentrate.

Figure 3 shows an improvement in the texture of the forehead, i.e. smoother skin, after 1 month of using Probiotic Concentrate.

Figure 4 shows a reduction in the number of fine lines in the eye area after 1 month of using Probiotic Concentrate.