Mediation role of gut microbiota in the association between ambient fine particulate matter components and cardiovascular disease: Evidence from a China cohort

Abstract

Background

Pairwise associations among fine particulate matter (PM_2.5), gut microbiota, and cardiovascular disease (CVD) have been established. However, the mediating role of gut microbiota in the relationship between PM_2.5 and its components and CVD remains unclear.

Methods

We included 1459 participants from the China Multi-Ethnic Cohort between May 2018 and September 2019. CVD was identified using ICD-10 codes based on hospital surveillance system. PM_2.5 and its components were sourced from the ChinaHighAirPollutants dataset. Gut microbiota was obtained from 16S rRNA sequencing of stool samples, and five α-indexes along with 1088 gut compositions were used as mediators. Cox proportional hazards and multiple linear regression were used to explore the associations among PM_2.5 and its components, gut microbiota, and CVD. Causal mediation analysis was conducted to evaluate the potential mediating role of gut microbiota between PM_2.5 and its components and CVD.

Results

Among all the participants, 204 (14.0 %) had developed CVD during a 5501 person‐year follow‐up (median, 3.8 years). The ACE, Chao1, and Obs indexes positively mediated the associations of PM_2.5 and its components with both CVD and stroke, with mediation proportions ranging from 7.9 % to 8.9 % for CVD and 10.0 %–12.1 % for stroke. The ACE index had the highest mediation proportion (12.1 %) in the relationship between sulfate and stroke. The genus Pasteurella also demonstrated a mediating role, accounting for 2.6 %–3.2 % for CVD, and 2.5 %–3.6 % for stroke, exhibiting the highest mediation proportion (3.6 %) on the association between black carbon or nitrate and stroke.

Conclusion

Three α-indexes (ACE, Chao1, and Obs) and the Pasteurella positively mediated the association between PM_2.5 and its components and CVD risk. Enhancing the richness of gut microbiota could potentially reduce the risk of CVD induced by PM_2.5 and its components.