Association between gut microbiota diet index and cardiovascular disease in US adults: a cross-sectional study of NHANES 2007–2018

BACKGROUND: The Dietary Index for Gut Microbiota (DI-GM), a recently developed metric designed to evaluate diet quality in relation to gut microbiota, has an uncharted connection with cardiovascular diseases (CVD). METHODS: We collected cross-sectional data from 8,533 participants in the National Health and Nutrition Examination Survey (NHANES) conducted between 2007 and 2018. Cardiovascular disease (CVD) was defined as a combination of self-reported physician diagnoses and standardized medical status questionnaires. Dietary recall data were utilized to calculate the DI-GM), which includes components that are both beneficial and unfavorable to gut microbiota. All analyses incorporated NHANES sample weights, stratification, and primary sampling units to account for the complex multistage probability sampling design. Logistic regression and Restricted cubic splines (RCS) were employed to explore the associations among DI-GM, beneficial gut microbiota, and CVD. RESULTS: The control group had significantly higher DI-GM and beneficial gut microbiota score than the disease group (p < 0.05). Inverse associations were observed between DI-GM, beneficial gut microbiota score and the prevalence of cardiovascular disease (OR = 0.93, 95% CI = 0.89-0.97; OR = 0.88, 95% CI = 0.83-0.92). Moreover, RCS showed a linear relationship between DI-GM and cardiovascular disease.Subgroup analysis revealed stronger inverse associations between DI-GM and CVD among older individuals or those with hypertension or diabetes. CONCLUSIONS: A higher DI-GM was associated with a lower prevalence of CVD. Future studies are supposed to validate these findings by employing longitudinal studies.