Microbiome dysbiosis in psoriatic skin among Asian populations:Insights from a systematic review and meta-analysis

Background: Psoriasis is a chronic immune-mediated skin disease increasingly associated with microbial dysbiosis. Objective: To clarify patterns of skin microbiome alteration in psoriasis. Methods: We conducted a systematic review and meta-analysis of Asian cohort studies. Eleven studies were included. Results: Results for α-diversity were inconsistent, with Shannon and Simpson indices showing heterogeneous outcomes. In contrast, genus-level analysis revealed consistent taxonomic trends: psoriatic lesions demonstrated enrichment of Staphylococcus and Streptococcus with concurrent depletion of Cutibacterium. Fungal analyses showed redistribution of Malassezia species, with increased burden reported in Japanese, Chinese, and Iranian cohorts. Funnel plots indicated limited publication bias, and sensitivity analyses confirmed that exclusion of therapeutic cohorts did not alter results. Importantly, IL-17A inhibitor studies demonstrated partial restoration of microbial balance following treatment. These findings provide reproducible evidence of microbiome shifts in psoriatic skin across Asian populations. The results suggest that specific bacterial and fungal taxa may serve as biomarkers of disease activity and therapeutic response. Conclusion: Future mechanistic work should integrate microbiome and host immune pathways to advance development of microbiome-targeted interventions in psoriasis.