Causal Relationship Between Gut Microbiota and Cataract: A Two-Sample Bidirectional Mendelian Randomization Study.

Area of Science:

• Microbiome research
• Ophthalmology
• Genetic epidemiology

Background:

• Cataracts are a leading cause of blindness globally.
• The gut microbiota's role in systemic diseases is increasingly recognized.
• Understanding gut-eye axis connections is crucial for novel therapeutic strategies.

Purpose of the Study:

• To investigate the potential causal relationship between gut microbiota composition and cataract risk.
• Employ a two-sample Mendelian randomization (MR) approach to assess causality.

Main Methods:

• Utilized genome-wide association study (GWAS) data for gut microbiota (18,340 participants) and cataracts (8,890 cases, 454,120 controls).
• Applied inverse variance weighted (IVW) as the primary analysis method.
• Confirmed findings using weighted median, MR-Egger regression, and MR-PRESSO tests for robustness.

Main Results:

• Identified suggestive associations between five bacterial traits and cataract risk.
• ChristensenellaceaeR.7, Sellimonas, and Eubacterium ruminantium showed negative correlations with cataract risk.
• Eggerthella and Odoribacter exhibited positive associations with cataract risk.
• No significant heterogeneity was detected among the associated bacterial traits.

Conclusions:

• The findings support a potential causal role for the gut microbiota in cataract development.
• Further research is warranted to elucidate the specific mechanisms linking gut microbiota to cataractogenesis.