An approach on the potential use of probiotics in the treatment of skin conditions: acne and atopic dermatitis.

Acne and Atopic Dermatitis (AD) are chronic inflammatory skin conditions with severe impact on a patient's life. Current treatments are related to adverse effects and do not represent a definitive cure. The present paper reviews the alterations in skin microbiome, specifically in acne and AD, and aims in searching for potential treatments based on benefic microorganisms, called probiotics. The review was made through bibliographic search of the main databases (Science Direct, PubMed, Scielo, Medline) between September 2015 and June 2016. Acne lesions create an environment that facilitates the excess growth of Propionibacterium acnes (P. acnes). AD is related to an increase in the proportion of Staphylococcus aureus (S. aureus) during flare-ups. Some microorganisms have been shown to act not only in the prevention but also in the competition for pathogenic microorganisms and beneficially affect the inflammatory process present in these conditions. Despite the high variety of tested bacteria, Staphylococcus, Streptococcus, Lactococcus, Lactobacillus, and Enterococcus are the ones which showed the highest potential to control acne, and Vitreoscilla filiformis (V. filiformis), Staphylococcus epidermidis (S. epidermidis), and species of Lactobacillus and Bifidobacterium in the treatment of AD. Many of these studies were in vitro, and more detailed research should be performed in order to prove the real efficacy and safety of probiotics in these situations. An interesting alternative seems to be the use of Bacteriocin-like inhibitory substances produced by probiotics, responsible for their antimicrobial activity.