Ocular bacterial microbiome analysis by next-generation sequencing in patients with Stevens-Johnson syndrome and Sjögren's disease: associations with dry eye indices

The ocular surface microbiome plays a crucial role in maintaining immune homeostasis, and its disruption may contribute to mucosal inflammation and autoimmunity. This pilot exploratory study investigated and compared the ocular surface bacterial microbiome in patients with Stevens-Johnson syndrome (SJS), Sjögren's disease (SjD), and healthy controls using next-generation sequencing (NGS) and correlated these findings with dry eye parameters. Conjunctival swabs were collected from sixteen individuals: ten with SJS, three with SjD, and three healthy controls. Dry eye parameters were employed to evaluate the dry eye disease. Microbiome profiles were determined by the NGS of the 16S V3-V4 region and analyzed using the SILVA database. The microbiome exhibited notable differences at the genus level among the SJS group. Specifically, the abundance of Staphylococcus was significantly lower in the SJS group compared to both the SjD and healthy controls (p = 0.04). In contrast, increased levels of Streptococcus and Corynebacterium were associated with higher scores on the Dry Eye Disease of Dry Eye Workshop (DED DEWS score) (p = 0.003) and the Ocular Surface Disease Index (OSDI) score (p = 0.01), respectively. Conversely, elevated levels of Cutibacterium and Pseudomonas were associated with more severe dry eye, as evidenced by lower Schirmer I test results (p = 0.003) and tear break-up time (TBUT) values (p = 0.05). In contrast, the ocular microbiome of SjD patients was similar to that of healthy controls. In conclusion, patients with SJS exhibited distinct changes in the ocular microbiota, with specific bacterial genera associated with dry eye severity, suggesting a potential role for microbial alterations in the ocular surface inflammation.