Gut microbiota and childhood asthma: A 2-sample bidirectional Mendelian randomization study

Area of Science:

• Microbiome research
• Pediatric pulmonology
• Genetic epidemiology

Background:

• The link between the gut microbiota and childhood asthma is not well understood.
• Investigating this relationship is crucial for developing effective prevention and treatment strategies.

Purpose of the Study:

• To investigate the potential causal relationship between the human gut microbiota and childhood asthma using a bidirectional, 2-sample Mendelian randomization (MR) analysis.
• To identify specific gut microbial taxa associated with the risk of developing childhood asthma.

Main Methods:

• Utilized publicly available genome-wide association study (GWAS) summary data for 2-sample MR analysis.
• Employed inverse variance weighted (IVW) meta-analysis for primary causal effect estimation.
• Conducted sensitivity analyses including weighted median, MR-Egger, and MR-PRESSO, along with Cochran Q test, MR-Egger intercept test, and leave-one-out analysis to assess robustness and pleiotropy.
• Performed reverse MR analysis to investigate potential reverse causation.

Main Results:

• MR analysis indicated a potential causal link between gut microbiota composition and childhood asthma risk.
• Specific microbial taxa, including class Coriobacteriia, family Coriobacteriaceae, genus Bilophila, and order Enterobacteriales, were inversely associated with childhood asthma risk (e.g., OR=0.807, P=0.036 for Coriobacteriaceae).
• Genus Catenibacterium showed a positive association with childhood asthma risk (OR=1.201, P=0.031).
• Reverse MR identified negative correlations between childhood asthma and genera Blautia, Marvinbryantia, Ruminococcus1, Tyzzerella3, and phylum Lentisphaerae.

Conclusions:

• The findings provide evidence supporting a causal role of gut microbial communities in the etiology of childhood asthma.
• These insights may inform the development of microbiota-directed prevention strategies for childhood asthma.
• The study highlights the potential for identifying microbial biomarkers for asthma diagnosis in children.