Causal association between gut microbiota and pulmonary embolism: a 2-sample Mendelian randomization study

Abstract Background Pulmonary embolism (PE) is the third most common cause of cardiovascular-related deaths globally; however, the causal relationship between gut microbiota and PE remains unclear. This study aimed to explore the impact of gut microbiota on PE. Methods This study utilized a 2-sample Mendelian randomization (MR) design to analyze gut microbiota genome-wide association study data from the MiBioGen database and PE data from the FinnGen database. Statistical methods, such as inverse variance-weighted, MR-Egger, weighted median, and weighted modes, were used to investigate the causal relationship between the gut microbiota and PE. Moreover, a sensitivity analysis was conducted to assess the robustness of the results. Results MR analysis revealed that gut microbiota genera Intestinimonas (odds ratio [OR]: 0.797; 95% confidence interval [CI]: 0.666–0.952; P = 0.013) and Roseburia (OR: 0.752; 95% CI: 0.575–0.984; P = 0.038) have a protective effect on PE. Conversely, an increased abundance of the phylum Lentisphaerae (OR: 1.217; 95% CI: 1.033–1.434; P = 0.019), class Lentisphaeria (OR: 1.219; 95% CI: 1.010–1.471; P = 0.039), order Gastranaerophilales (OR: 1.209; 95% CI: 1.017–1.437; P = 0.031), order Victivallales (OR: 1.219; 95% CI: 1.010–1.471; P = 0.039), and the genus Ruminococcus gauvreauii (OR: 1.274; 95% CI: 1.015–1.599; P = 0.037) increases the risk of developing PE. Sensitivity analysis indicated no heterogeneity or horizontal pleiotropy. Conclusion Seven gut microbiotas, including the phylum Lentisphaerae, class Lentisphaeria, orders Gastranaerophilales and Victivallales, and genera R. gauvreauii , Intestinimonas , and Roseburia , were causally associated with PE. These findings may contribute significantly to the prevention of PE through dietary modifications and microbiome interventions.