Characterization of the Gut Microbiota in Patients with Psoriasis: A Systematic Review

Background: Psoriasis is a prevalent and persistent inflammatory disorder with systemic manifestations. Emerging evidence implicates the gut microbiota in regulating inflammatory responses, metabolic pathways, and immune homeostasis. This review synthesizes current evidence on gut microbiota dysbiosis in psoriasis and evaluates the therapeutic potential of probiotics and fecal microbiota transplantation (FMT) in disease management. Method: Following PRISMA guidelines, we systematically reviewed studies investigating gut microbiome profiles in psoriasis through the MEDLINE, EMBASE, and Web of Science databases (January 2015-December 2024). Included studies utilized 16S rRNA gene sequencing or metagenomic analyses for microbial characterization. Results: Comparative analyses revealed distinct gut microbiota patterns in psoriasis patients compared with healthy controls, although specific microbial signatures exhibited inconsistencies across studies. Notably, interventions modulating gut microbiota composition-particularly probiotic supplementation-demonstrated measurable improvements in psoriasis severity scores and inflammatory markers. Conclusions: Gut microbiome modulation represents a promising therapeutic strategy for psoriasis; however, current evidence highlights the need for standardized microbial analysis methodologies and larger longitudinal studies to establish causality. Future research should prioritize the functional characterization of microbiota-host interactions to optimize therapeutic applications.