Skin and Gut Microbiota in Psoriasis: A Systematic Review

Paying attention to a microbial approach may lead to improvements in diagnosis, treatment, prevention, and prognosis of psoriasis. A systematic review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines searching strategy to identify the pattern of the microbiome and the association of skin and gut microbiota with psoriasis, including the factors that may affect the results of the microbial study. In total, 16 studies were included in this systematic review. Ten studies investigated the skin microbiome, of which six studies were cross-sectional and four studies were prospective studies. Six studies investigated the gut microbiome, including five cross-sectional studies and one prospective study. The understanding of the relationship between microbiota and psoriasis may lead to diagnostics and treatment improvements. Currently, there is a slight consensus on some specific features that define psoriasis. However, no specific taxa have been identified as biomarkers of the disease, even from large-scale cohort studies. Thus, future cohort studies with standardized methodologies and proof-of-concept investigations in animal models may uncover the role of microbiota and the microbial pathways in psoriasis.