Objective:

To investigate the role of intestinal dysbiosis in age-related cataract (ARC) and its potential contributions to cataract pathogenesis.

Approach:

• Study Design: Analysis of stool samples from 30 patients with ARC and 30 healthy controls using 16S rDNA sequencing, untargeted metabolomics, and targeted short-chain fatty acid (SCFA) profiling.

Key Findings:

• Patients with cataract exhibited a more dysbiotic microbiome profile despite no significant difference in overall microbial diversity.
• Distinct fecal metabolomic signatures were observed in ARC patients, particularly in glycerophospholipid and choline metabolism pathways.
• A total of 430 metabolites differed between cataract patients and controls, with lipid metabolites being the majority.
• Key anti-inflammatory SCFAs (acetate, propionate, butyrate) were significantly reduced in ARC patients, correlating with the abundance of beneficial SCFA-producing bacteria.

Interpretation:

Altered lipid metabolism and reduced SCFA signaling may promote chronic systemic inflammation and oxidative stress, accelerating lens opacification.

Limitations:

• The study cohort was relatively small.
• The cataract group was modestly older than controls.
• The cross-sectional design limits conclusions about causality.

Conclusion:

The study supports the concept of a gut–eye axis in ocular disease and suggests potential for stool-based microbial or metabolic biomarkers in cataract risk assessment.

Sources:

• Scientific Reports