ABSTRACT

Aims:
The gut microbiota is a key mediator linking diet to cardiovascular disease (CVD). We aimed to evaluate the association of the dietary index for gut microbiota (DI-GM) with CVD risk, and jointly with the Life's Essential 8 (LE8) score for cardiovascular health.

Methods and results:
We included 200 690 UK Biobank participants and 30 180 National Health and Nutrition Examination Survey (NHANES) participants. The DI-GM score was calculated from 24-h dietary recalls. The LE8 score was generated from 8 metrics. The main outcome was incident (UK Biobank) and prevalent (NHANES) CVD. We used multivariable Cox proportional hazards and logistic regression models to assess associations. In UK Biobank, during a median follow-up of 13.33 years (interquartile range: 12.66-14.16), 24 581 incident CVD events were identified. Compared with the low DI-GM group, the high DI-GM group had a 6% lower risk of CVD (Hazard Ratio [HR]: 0.94; 95% confidence interval [CI]: 0.91-0.97). These findings were consistent in NHANES (Odds Ratio: 0.78; 95% CI: 0.63-0.97). The inverse association of a high DI-GM was significant even among individuals with suboptimal cardiovascular health as defined by LE8 (HR: 0.77; 95% CI: 0.66-0.89). A significant additive interaction was observed between DI-GM and LE8 (all P values <0.05).

Conclusion:
In two large Western populations, greater adherence to a gut microbiota-friendly diet was associated with a lower risk of CVD. This benefit is additive to improvements in LE8 cardiovascular health and is particularly relevant for individuals at high risk. These findings support the integration of gut-focused dietary strategies into CVD prevention.

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