AIM: To investigate the potential causal relationship between gut microbiota(GM)and primary open-angle glaucoma(POAG)based on a two-sample Mendelian randomization(MR)analysis.

METHODS: The exposure data was derived from the Genome-Wide Association Studies(GWAS)of GM at the University of Bristol, while the outcome data for POAG was sourced from the MRC Integrative Epidemiology Unit(IEU)Open GWAS database. In this study, inverse variance weighted(IVW), MR Egger, weighted median(WM), Simple Mode, and Weighted Mode were analyzed to investigate the potential causal relationships between GM and POAG. IVW was used as the primary method for this study, and sensitivity analysis was conducted to assess the reliability of the MR analysis.

RESULTS: The IVW analysis revealed that Butyrivibrio(OR=1.170, 95%CI: 1.057-1.295, P=0.002), Howardella(OR=1.188, 95%CI: 1.043-1.355, P=0.010), and LachnospiraceaeUCG001(OR=1.229, 95%CI: 1.016-1.485, P=0.033)were correlated with the risk of POAG. Conversely, Candidatus Soleaferrea(OR=0.810, 95%CI: 0.670-0.981, P=0.031), Ruminococcustorquesgroup(OR=0.656, 95%CI: 0.453-0.950, P=0.026), and RuminococcaceaeUCG013(OR=0.770, 95%CI: 0.598-0.990, P=0.041)were protective factors for POAG. Sensitivity analysis showed that there were no heterogeneity and pleiotropy among the instrumental variables.

CONCLUSION: The MR study indicated a causal relationship between GM and POAG. Given the sight-threatening characteristic of POAG, early identification and intervention in the relative factors was significant for the prognosis of POAG.