Association between gut microbiota and sensorineural hearing loss: a Mendelian randomization study

Area of Science:

• Microbiome research
• Genetics
• Otolaryngology

Background:

• Emerging evidence suggests a link between gut microbiota and sensorineural hearing loss (SNHL), proposing a gut-inner ear axis.
• The precise causal relationship between gut bacteria and SNHL remains unclear.
• This study aims to clarify the causal effect of gut microbiota on SNHL using a robust analytical approach.

Purpose of the Study:

• To determine the causal effect of gut microbiota on sensorineural hearing loss (SNHL).
• To identify specific gut microbial taxa associated with SNHL risk or protection.
• To provide evidence supporting the gut-inner ear axis hypothesis.

Main Methods:

• A two-sample Mendelian randomization (MR) analysis was conducted.
• Genome-wide association study data for gut microbiota (n=18,340) and SNHL (28,310 cases, 302,750 controls) were utilized.
• Standard MR methods (IVW, MR-Egger, weighted median) and sensitivity analyses were employed to ensure result validity.

Main Results:

• *Lachnospiraceae (UCG001)* showed a significant protective effect against SNHL (OR=0.85, P=6.99 × 10^-4).
• *Intestinimonas* exhibited a suggestively protective effect (OR=0.89, P=8.53 × 10^-3).
• *Rikenellaceae (RC9gutgroup)* and *Eubacterium (hallii group)* were suggestively associated with an increased SNHL risk (ORs > 1, P < 0.05).
• Reverse MR analysis indicated no significant causal effect of SNHL on gut microbiota. No significant heterogeneity or pleiotropy was detected.

Conclusions:

• The identified gut bacterial genera associated with SNHL provide support for the gut-inner ear axis.
• These findings highlight potential microbial biomarkers for SNHL prevention and treatment strategies.
• Further research is warranted to elucidate the underlying mechanisms of the gut microbiome's influence on inner ear health and disease.