The potential of probiotics for treating acne vulgaris: A review of literature on acne and microbiota

Acne is known as a chronic inflammatory skin disease with sever adverse effects on quality of life in the patients. The increasing resistance to antibiotics has decreased their effectiveness in treating acne. As viable microbial dietary supplements, probiotics provide health benefits through fighting pathogens and maintaining the homeostasis of the gut and skin microbiome. The present article reviewed the potential of probiotics as beneficial microorganisms for treating acne vulgaris. This review of literature was conducted through a bibliographic search of popular databases, including Science Direct, PubMed, Scielo and Medline, using keywords such as probiotics, prebiotics, synbiotics, microbiome, and acne vulgaris to determine potential applications of these beneficial microbiomes in treating acne vulgaris. Acne lesions are associated with increases in proportion of Propionibacterium acnes as a skin commensal bacterium. The environmental studies showed inhibitory effects of probiotics on P. acnes, mediating by antibacterial proteins and bacteriocin-like inhibitory substances, and their immunomodulatory effects onkeratinocytes and epithelial cells. Probiotics were also found to inhibit cytokine IL-8 in epithelial cells and keratinocytes, suggesting immunomodulatory activities. Moreover, glycerol fermentation by Staphylococcus epidermidis was found to be a natural skin defense against acne and an overgrowth inhibitor of P. acnes. As an antimicrobial agent in lotions and cosmetic formulations, Lactococcus sp. can decrease the inflammatory mediators that are produced by P. acnes and cause vasodilation, edema, mast cell degranulation and TNF-alpha release. Oral administration of probiotics was found to constitute an adjuvant therapy to conventional modalities for treating mild-to-moderate acne vulgaris.