Gut Microbiome in Stevens-Johnson Syndrome and Sjögren’s Disease: Correlations with Dry Eye

Changes in gut microbial composition may influence mucosal immune responses and contribute to systemic autoimmune manifestations. This study aimed to investigate and compare the gut microbiome in patients with Stevens-Johnson syndrome (SJS), Sjögren’s disease (SjD), and healthy controls, using next-generation sequencing (NGS), and correlate with dry eye parameters. Fecal samples from ten SJS, ten SjD, and ten healthy controls were analyzed. Dry eye parameters were employed to evaluate the dry eye disease (DED). Microbiome profiles were determined by next-generation sequencing of the 16S V3-V4 region and analyzed using the Silva database. The gut microbiome showed significant differences in the SJS group, including a reduced Chao 1 index (p = 0.01) that was progressively correlated with increased ocular severity and a decrease in Faecalibacterium (p = 0.048) compared to the healthy control group. In SJS, strong correlations were observed between Christensenellaceae and DEWS score (p = 0.04), Subdoligranulum and NEI score (p = 0.04), and Clostridia and TBUT (p = 0.009). In contrast, the gut microbiome of SjD patients was similar to that of healthy controls. Patients with SJS exhibited distinct alterations in gut microbial composition, characterized by reduced microbial richness and depletion of Faecalibacterium. Furthermore, specific bacterial genera were significantly associated with the severity of dry eye, suggesting a potential link between alterations in the gut microbiome and ocular surface inflammation.