Gut microbiota dysbiosis and altered fecal metabolome in patients with age-related cataract

Age-related cataract (ARC) is a leading cause of vision loss whose underlying mechanisms remain incompletely understood. Emerging evidence suggests the gut microbiota can influence ocular health via systemic metabolic and inflammatory pathways, yet the gut–eye connection in cataract has not been explored. We aimed to characterize gut microbial communities and fecal metabolic profiles in ARC patients.

Fecal samples from 30 ARC patients and 30 age- and sex-matched healthy controls were collected and analyzed. Gut microbiota composition was profiled by 16S rDNA gene sequencing, and untargeted fecal metabolomics was performed by liquid chromatography–mass spectrometry (LC–MS). Additionally, eight short-chain fatty acids (SCFAs) were quantified by targeted gas chromatography–mass spectrometry (GC–MS). Differences in microbial taxa and metabolites were identified using multivariate statistics (PCA, PLS-DA/OPLS-DA) and differential abundance testing (VIP>1, p<0.05 after FDR correction).