Dietary Index for Gut Microbiota and Risk of All-Cause and Cardiovascular Mortality Across...

Cardiovascular-kidney-metabolic (CKM) syndrome represents a progressive disorder characterized by the interplay of cardiovascular pathologies, chronic renal impairment, and metabolic dysregulation. Therefore, this study aimed to examine the relationship between the dietary index for gut microbiota (DI-GM) and mortality outcomes, including both all-cause and cardiovascular-specific mortality, in individuals classified with CKM syndrome stages 0-3.

Our study cohort consisted of 7884 adult participants aged 30-79 years from the National Health and Nutrition Examination Survey (NHANES) conducted between 2007 and 2018. Dietary intake data obtained through 24-hour dietary recalls and food frequency questionnaires were used to calculate the DI-GM scores, incorporating both components beneficial to the microbiota and those with potentially detrimental nutritional effects. The primary and secondary endpoints were all-cause mortality and cardiovascular-related mortality, respectively. The Kaplan-Meier survival analysis, Cox proportional hazards regression models, and restricted cubic spline (RCS) techniques were employed in the statistical analyses.

The participants had a median age of 50 years, with females comprising 52.97% of the cohort. Over a median follow-up period of 77 months, we documented 469 all-cause deaths (4.56%) and 105 cardiovascular fatalities (1.02%). Elevated beneficial scores for the DI-GM demonstrated significant inverse associations with both all-cause (p < 0.001) and cardiovascular mortality (p = 0.017). However, while the total DI-GM scores showed correlation with decreased all-cause mortality (p < 0.001), no significant association emerged for cardiovascular mortality. Following the employment of a comprehensive adjustment, the hazard ratio (HR) for the total DI-GM score and all-cause mortality was 0.90 (95% confidence interval (CI): 0.82-0.98). For the beneficial components, the HR was 0.88 (95% CI: 0.79-0.98) for all-cause mortality and 0.87 (95% CI: 0.77-0.99) for cardiovascular mortality. RCS modeling revealed a U-shaped correlation between the total DI-GM scores and all-cause mortality, which was in contrast to a linear association for the beneficial scores. The systemic inflammation index (SII) accounted for 5.29% and 8.45% of the observed associations between the total and beneficial DI-GM scores and all-cause mortality, respectively.

Elevated DI-GM dietary scores, particularly those emphasizing food components beneficial to the gut microbiota, demonstrate protective associations against both all-cause and cardiovascular mortality in individuals with CKM syndrome in stages 0-3. These protective effects appear partially influenced by systemic inflammatory pathways.