Exploring the potential causal association between oral microbiota and heart failure using Mendelian randomization in an East Asian population

Growing evidence suggests that the gut microbiota is closely associated with the risk of developing heart failure (HF). However, the potential impact of oral microbiota on HF has received far less attention. Using instrumental variable from the latest genome-wide association study data in East Asian populations, we evaluated the genetic predisposition to HF associated with 455 salivary microbiota and 540 tongue microbiota. The HF dataset was derived from Biobank Japan, including 9413 HF cases and 203,040 controls. The inverse-variance weighted method was used to assess potential causal associations between oral microbiota and HF. Robustness of the results was confirmed through MR-Egger regression intercept test and MR-PRESSO global test. Inverse-variance weighted analysis identified 33 tongue microbiota, including Veillonella atypica 1903 (odds ratio [OR] = 0.84, 95% confidence interval [CI]: 0.74-0.97, P = .013), and 28 salivary microbiota, including Centipeda massiliensis 3300 (OR = 0.79, 95% CI: 0.67-0.94, P = .007), that may be negatively associated with HF. Conversely, 25 tongue microbiota, such as Streptococcus pneumoniae 1744 (OR = 1.50, 95% CI: 1.16-1.94, P = .001), and 30 salivary microbiota, including Fusobacterium massiliense 586 (OR = 1.50, 95% CI: 1.31-1.63, P = .017), showed a potential positive association with HF. Sensitivity analyses confirmed the stability of these results. This study has preliminarily identified multiple oral microbiota that may have a causal association with the risk of developing HF, providing a more reliable theoretical basis for exploring the microbiota-related mechanisms underlying HF.