Gut Microbiota and Psoriatic Arthritis: From Pathogenesis to Microbiota-Targeted Therapies

Background/Objectives: Psoriatic disease (PsD) is a chronic, systemic inflammatory disorder characterized by a wide spectrum of clinical manifestations extending beyond skin and joint involvement. Increasing evidence suggests a relevant role of the gut microbiota in the pathogenesis of psoriatic arthritis (PsA), although a clear causal relationship remains to be fully established. The aim of this review is to summarize current evidence on the role of the gut microbiome in PsD, with a focus on immune modulation, disease pathogenesis and potential therapeutic implications. Methods: A narrative review of the literature was conducted, focusing on studies investigating gut microbiota composition, dysbiosis patterns, and microbiome-related mechanisms in PsD and PsA, as well as emerging microbiota-targeted interventions. Results: Recent advances in high-throughput sequencing technologies have identified distinct microbial signatures associated with PsA onset and progression. Dysbiosis appears to influence immune system regulation, contributing to systemic inflammation through mechanisms involving intestinal barrier dysfunction and immune activation. Patients with PsA exhibit specific alterations in gut microbial composition compared to healthy controls. Emerging therapeutic strategies targeting the microbiota—including dietary interventions, probiotics, and fecal microbiota transplantation—show potential as adjunctive approaches in disease management, although clinical evidence remains limited. Conclusions: The gut microbiome represents a promising area of research in PsD, offering novel insights into disease mechanisms and potential therapeutic targets. Further studies are needed to clarify causal relationships and to define the clinical applicability of microbiota-based interventions.