Investigating the Causal Relationship Between Gut Microbiota and Allergic Conjunctivitis: A Two-Sample Mendelian...

Area of Science:

• Microbiome research
• Ophthalmology
• Human genetics

Background:

• Allergic conjunctivitis is a common ocular condition.
• The role of gut microbiota in allergic diseases is increasingly recognized.
• Understanding causal links can inform novel therapeutic strategies.

Purpose of the Study:

• To investigate the potential causal association between gut microbiota composition and allergic conjunctivitis.
• To identify specific gut bacteria that may influence the risk of developing allergic conjunctivitis.

Main Methods:

• A two-sample Mendelian randomization (MR) analysis was conducted.
• Utilized summary statistics from large-scale genome-wide association studies (GWAS) for gut microbiota (MiBio-Gen, n=18,340) and allergic conjunctivitis (IEU Open GWAS, n=218,792).
• Employed F-statistics, sensitivity analyses, and reverse MR to ensure robustness and rule out reverse causality.

Main Results:

• The phylum Euryarchaeota demonstrated a protective association against allergic conjunctivitis (OR=0.87, p=6.17×10⁻⁴).
• Several bacterial taxa, including the genus Christensenellaceae R.7 group, family Peptostreptococcaceae, and genus Lachnospiraceae FCS020 group, also showed suggestive protective effects.
• Sensitivity analyses confirmed the reliability of these findings, and reverse MR analysis found no significant reverse causal relationship.

Conclusions:

• Gut microbiota, particularly the phylum Euryarchaeota, may play a causal role in the development of allergic conjunctivitis.
• These findings offer novel insights into the gut-eye axis and potential targets for preventing and treating allergic conjunctivitis.