Identification of two probiotic strains able to prevent skin inflammation in a murine model

Objective: The purpose of our study was to investigate the effect of three probiotic strains on skin homeostasis in a model of inflammation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). Methodology: Four groups of 6 mice received one of the probiotic strains (Lactobacillus salivarius LA307, Lactobacillus rhamnosus LA305 or Bifidobacterium bifidum S12; 3.109 CFU/day) or the vehicle by orogastric gavage daily for three consecutive weeks starting two weeks before the induction of skin inflammation. Macroscopic and microscopic evaluation of skin inflammation were performed as well as measurement of cytokine serum levels. Results: Treatment with LA305 or LA307 strains reduced the severity and extension of TPA-induced skin lesions with significantly lowered macroscopic and microscopic scores. It also led to a significant decrease in serum levels of pro-inflammatory cytokines and a significant increase of anti-inflammatory cytokines. The observed modifications were more pronounced with LA307 than LA305 and S12. Discussion: The probiotic strains LA305 and LA307 can prevent the development of skin inflammation and could be good candidates for preserving skin integrity and homeostasis. Cytokine analysis indicated that these effects are at least in part due to anti-inflammatory actions. Further studies will be needed to elucidate the mechanisms of action involved.