ObjectiveAccumulating evidence indicates that alterations in the oral composition of the oral microbiota are associated with asthma. However, it remains uncertain whether these associations reflect causal relationships. The study aimed to investigate the causal relationship between oral microbiota and asthma at the genetic level. MethodsA two-sample Mendelian randomization (MR) analysis was conducted using genome-wide association studies (GWAS) data on the oral microbiota and asthma with in the East Asian population. Inverse-variance weighted (IVW), MR-Egger, weighted median, and weighted mode methods were utilized, to examine the potential causal relationship between oral microbiota and asthma. Additionally, pleiotropy and heterogeneity tests were conducted to assess the robustness of the findings. ResultsAmong the 3, 117 bacterial taxa analyzed, nine genera, comprising 18 oral microbiota, that exhibited causal effects on asthma. Twelve oral microbiota, including Streptococcusᵤmgs₁936, Porphyromonasₘgs₃421, and CampylobacterAᵤmgs₃382, demonstrated positive causal associations with asthma. Conversely, six oral microbiota, including Parvimonasᵤmgs₂046, and Parvimonasᵤmgs₃325, were negatively related to asthma. Enrichment was observed in three genera: Parvimonas, Streptococcus, and TM7x. No pleiotropy or heterogeneity was detected among the instrumental variables (IVs) throughout the study. Conclusions.
Wei et al. (Sat,) studied this question.