Gender-specific protective effects of dietary index for gut microbiota on cardiovascular disease: insights from NHANES 2007–2020

Abstract

Background: Cardiovascular disease (CVD) represents a significant global health burden. The gut microbiome, as a potential regulatory factor, and its synergistic interaction with dietary patterns remains underexplored. The dietary index for gut microbiota (DI-GM), which quantifies the impact of diet on gut microbiota, has limited evidence of DI-GM’s association with CVD, particularly regarding gender-specific effects and dose-response patterns. Methods: This study utilized data from the National Health and Nutrition Examination Survey (NHANES) 2007–2020, which included 24,111 adult participants. We employed multivariable logistic regression models to assess the relationship between DI-GM and CVD. To explore possible nonlinear associations, we carried out a restricted cubic spline (RCS) analysis. Furthermore, we conducted subgroup analysis, gender stratification analysis, and sensitivity analysis. Results: A 1-unit increase in DI-GM score was associated with a 4% reduction in CVD prevalence (adjusted OR = 0.96, 95% CI: 0.93–0.98, p = 0.002). Compared to the lowest quartile (Q1), the highest quartile (Q4) showed a 17% lower CVD prevalence (OR = 0.83, 95% CI: 0.72–0.95, p = 0.008). Subgroup analysis revealed a more pronounced association in women (OR = 0.95, 95% CI: 0.92–0.99, p = 0.026). Gender-stratified logistic regression and RCS confirmed a significant inverse linear relationship between DI-GM and CVD in women. Sensitivity analyses further validated the robustness of these findings. Conclusion: Dietary patterns with higher DI-GM scores were found to be linked to a lower prevalence of CVD, especially among women. These findings highlight DI-GM as a microbiota-targeted dietary strategy for CVD prevention. Prospective studies integrating multi-omics data are warranted to validate causality and elucidate sex-specific microbiota-mediated pathways.