Investigating the causal link between gut microbiota and dry age-related macular degeneration: a bidirectional Mendelian randomization study.

AIM

To assess the causal link between 211 gut microbiota (GM) taxa and dry age-related macular degeneration (dAMD) risk.

METHODS

Mendelian randomization using instrumental factors taken from a genome-wide association study (GWAS) were used. Inverse variance weighted (IVW) analysis and sensitivity analysis were performed on the FinnGen project, which included 5095 cases and 222 590 controls.

RESULTS

The IVW analysis showed substantial genus- and family-level relationships between GM taxa and dAMD risk. Specifically, the family (=0.03), genus (=3.91×10), genus (=6.55×10), and genus (=0.04) were linked to a higher risk of developing dAMD, while the genus (=7.75×10), genus (=0.04) and genus (=0.04) exhibited a protective effect against dAMD. No significant causal relationships were observed at higher taxonomic levels. Additionally, in the reverse IVW analysis, no meaningful causal effects of the 7 GM taxa.

CONCLUSION

These findings give support for the gut-retina axis participation in dAMD and shed light on putative underlying processes. Investigations on the connection between GM and dAMD have not yet revealed the underlying mechanism.