Analysis of the gut and oral microbiome in patients with Stevens-Johnson syndrome and Sjögren’s disease: associations with dry eye severity

To investigate and compare the gut and oral 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. Oral swabs were obtained from six SJS, three SjD, and three healthy controls. 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) progressively correlated with increased ocular severity and decreased Faecalibacterium (p = 0.05) compared to the respective healthy control group. Severe SJS cases showed elevated Prevotella in both microbiomes. Strong correlations were observed in SJS between Christensenellaceae and DEWS score (p = 0.04), Subdoligranulum and NEI score (p = 0.04), and Clostridia with TBUT (p = 0.009). In SjD, gut profiles resembled healthy controls. The oral microbiome was similar across groups, except for higher Prevotella and Veillonella levels in SJS and SjD patients. SJS patients exhibited gut dysbiosis, characterized by reduced microbial richness and a significant decrease in the abundance of Faecalibacterium. Certain bacterial genera were correlated with the severity of dry eye, suggesting a potential link between gut microbiome alterations and the clinical progression of the disease.