Skin Microbiome Profiling in Patients with Primary Sjögren Disease Compared to Healthy Individuals.

Primary Sjögren disease (SjD) is a systemic autoimmune disease characterized by inflammation of exocrine glands, most commonly leading to dry mouth and dry eyes. Although the etiology of SjD remains unclear, emerging evidence suggests that the microbiome modulates immune homeostasis. This study aimed to compare the skin microbiomes of SjD patients with those of healthy controls (HCs) using 16S rRNA gene sequencing. Taxonomic composition, alpha and beta diversity, and predicted functional profiles were evaluated. We observed a significant depletion of Cutibacterium and a marked reduction in microbial diversity in SjD patients. Beta diversity analyses revealed distinct clustering among groups. Functional prediction suggested the downregulation of metabolic pathways associated with microbial homeostasis. Our findings propose that alterations in the skin microbiota may contribute to SjD pathogenesis and serve as potential biomarkers or therapeutic targets.