A higher abundance of butyrate‐producing taxa in the gut is associated with lower glaucoma prevalence.

Aims/Purpose: Glaucoma is an eye disease that is the commonest cause of irreversible blindness worldwide. It has been suggested that gut microbiota can produce reactive oxygen species and pro‐inflammatory cytokines that may travel from the gastric mucosa to distal sites, such as the optic nerve head or trabecular meshwork. There is evidence for a gut‐eye axis, as microbial dysbiosis has been associated with retinal diseases. Here, we investigated the association between glaucoma prevalence and the gut microbiome. Moreover, we analysed the association of the gut microbiome with intraocular pressure (IOP; risk factor of glaucoma) and vertical cup‐to‐disc ratio (VCDR; quantifying glaucoma severity). Methods: The discovery analyses included participants of the Rotterdam Study and the Erasmus Glaucoma Cohort. A total of 225 glaucoma patients were matched on age and sex with 1247 participants without glaucoma. Stool samples were collected and used to generate 16S rRNA gene profiles. We assessed associations with 233 taxa. We used data from the TwinsUK and the Study of Health in Pomerania (SHIP) to replicate our findings. The TwinsUK dataset consisted of 32 participants with glaucoma and 1542 unrelated, unmatched participants without glaucoma. The SHIP dataset consisted of a total of 2546 participants. Results: Several butyrate‐producing taxa (e.g., Butyrivibrio, Caproiciproducens, Clostridium sensu stricto 1, Coprococcus 1, Ruminococcaceae UCG 007, Shuttleworthia) were associated with lower glaucoma prevalence, lower IOP, and smaller VCDR. The replication analyses confirmed the findings from the discovery analyses. Conclusions: Large human studies exploring the link between the gut microbiome and glaucoma are lacking. Our results support the hypothesis that microbial dysbiosis plays a role in the pathophysiology of glaucoma. This research may support future research into the mediating role of butyrate‐producing taxa in the relation between dietary intake and glaucoma. [ABSTRACT FROM AUTHOR]