Mendelian randomization analysis establishes a causal link between specific gut microbiome elements, such as Oxalobacteraceae and Eggerthella, and a decreased risk of glaucoma, while identifying associations with increased risk linked to Bilophila, LachnospiraceaeUCG010, and Ruminiclostridium 9, reinforcing the pivotal role of the gut microbiome in glaucoma susceptibility.

The following is a summary of “Effect of the gut microbiome in glaucoma risk from the causal perspective,” published in the January 2024 issue of Ophthalmology by Wu et al.

Researchers conducted a retrospective study to establish a causal link between the gut microbiome (GM) and the risk of glaucoma, bridging observational findings with conclusive evidence.

They employed two-sample bidirectional Mendelian randomization (MR) analyses to investigate the causal relationship between GM and glaucoma. Genome-wide association study summary statistics for 196 GM taxa (n=18,340) and glaucoma (18,902 cases and 358,375 controls) were acquired from MiBioGen and the FinnGen Consortium. Various MR methods, including inverse variance weighted, MR-Egger, weighted median, weighted mode, Mendelian Randomization Pleiotropy Residual Sum and Outlier, MR-Egger intercept, and Cochran’s Q statistical analyses, were utilized to complement MR results and conduct sensitivity analysis. Validation of causal effects was performed using an independent cohort from the Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol (MRC-IEU) Consortium (1715 cases and 359,479 controls).

The results of MR analysis showed that the family Oxalobacteraceae (OR 0.900, 95% CI 0.843 to 0.961, P=0.002) and the genus Eggerthella (OR 0.881, 95% CI 0.811 to 0.957, P=0.003) were associated with a decreased risk of glaucoma. Genus Bilophila (OR 1.202, 95% CI 1.074 to 1.346, P=0.001), LachnospiraceaeUCG010 (OR 1.256, 95% CI 1.109 to 1.423, P=0.0003), and Ruminiclostridium 9 (OR 1.258, 95% CI 1.083 to 1.461, P=0.003) were associated with an increased risk. The positive causal effect of LachnospiraceaeUCG010 (OR 1.002, 95% CI 1.000 to 1.004, P=0.033) on glaucoma was confirmed in an independent cohort.

Investigators concluded that MR confirms GM as a causal factor for glaucoma risk, solidifying its role in disease susceptibility.

Source: bmjophth.bmj.com/content/9/1/e001547