A LARGE-SCALE genetic analysis has found evidence of a causal link between specific gut microbiota and childhood asthma, offering potential pathways for future prevention and diagnostics.
Gut Microbiota and Childhood Asthma: A Causal Connection
While previous research has identified associations between gut microbiota and asthma, this study provides some of the first genetic evidence supporting a direct causal role. Using a bidirectional, two-sample Mendelian randomisation (MR) approach, researchers analysed genome-wide association study (GWAS) data to examine whether variations in gut microbiota composition could influence the risk of childhood asthma.
The analysis identified both protective and risk-enhancing microbial taxa. Specifically, increased levels of Coriobacteriia, Coriobacteriaceae, Bilophila, and Enterobacteriales were inversely associated with asthma risk, suggesting a protective effect. In contrast, higher abundance of Catenibacterium was positively associated with asthma risk. These findings indicate that certain microbial communities may play a direct role in modulating immune responses linked to paediatric asthma.
Robust Trial Design Supports Findings
The MR design minimised confounding and reverse causation by using genetic variants as instrumental variables. The primary causal estimates were generated using inverse variance weighted (IVW) meta-analysis, while sensitivity analyses, including MR-Egger, weighted median, and pleiotropy assessments, supported the robustness of the results.
To explore the possibility of reverse causality (i.e. asthma influencing gut microbiota), the researchers conducted a reverse MR analysis. This revealed that asthma may also shape the abundance of microbes such as Blautia, Marvinbryantia, Ruminococcus1, Tyzzerella3, and the phylum Lentisphaerae, all of which showed a significant inverse relationship with asthma risk.
New Directions for Prevention and Biomarker Development
This study strengthens the evidence for a gut-lung axis in early-life disease and highlights the gut microbiome as a promising target for asthma prevention strategies. The identification of specific taxa with protective or harmful associations opens new avenues for biomarker discovery and microbial interventions in paediatric populations.
By confirming a genetic link between gut microbiota and childhood asthma, this study lays the groundwork for microbiota-targeted prevention and diagnostic approaches in paediatric asthma care.
Reference
Li Y et al. Gut microbiota and childhood asthma: A 2-sample bidirectional Mendelian randomization study. Medicine (Baltimore). 2025;104(33):e44023.
