Exploring the Causal Association Between Oral Microbiome Abundance and Asthma Risk Using Two-Sample Mendelian...

Asthma is influenced by genetic and environmental factors, and emerging evidence suggests that the oral microbiome may play a role in its pathogenesis. This study aimed to explore the causal association between oral microbiome abundance and asthma risk using a two-sample Mendelian randomization (MR) approach.

We utilized genome-wide association studies (GWAS) data comprising 56,167 asthma cases and 408,442 controls of European ancestry, alongside 610 individuals from the Danish ADDITION-PRO cohort for oral microbiome analysis. We selected 267 single nucleotide polymorphisms (SNPs) linked to salivary microbiota as instrumental variables (IVs) with an F-statistic > 10. MR analyses were carried out using inverse variance weighted (IVW), MR-Egger, weighted median, and weighted mode methods, complemented by sensitivity analyses.

Our findings revealed a significant association between specific salivary microbiota and asthma risk. Notably, increased abundance of Genus Rothia was positively associated with asthma risk (IVW: OR = 1.03), while an unspecified Streptococcus species showed a negative correlation (IVW: OR = 0.97). Sensitivity analyses confirmed these results' robustness, with no signs of pleiotropy or significant heterogeneity.

The study suggests a causal relationship between specific oral microbiota and asthma risk, emphasizing the oral microbiome's potential significance in asthma pathogenesis.