• Elevated DI-GM scores correlate with a lower premature death and overall mortality. • Each one-point rise in DI-GM lowers premature death risk by 9% and all-cause mortality risk by 10%. • PhenoAge, KDM age, and homeostatic dysregulation partially mediate the relationship between DI-GM and mortality. The intestinal microbiota critically modulates physiological status and is shaped by nutritional intake. This research explored the correlation between the dietary index for gut microbiota (DI-GM) and premature death and all-cause mortality, focusing on the mediating effect of biological age. The longitudinal study drew upon information gathered from the National Health and Nutrition Examination Survey (NHANES) spanning 2007–2018, with mortality data linked through 2019. DI-GM scores derived from nutritional values. Premature death and all-cause mortality were the primary endpoints. Biological age was assessed using PhenoAge (PA), the Klemera-Doubal Method (KDMAge), and homeostatic dysregulation (HD). The correlation between DI-GM and mortality was analyzed through Kaplan-Meier curves, Cox regression, smooth curve fitting, subgroup analysis, and mediation analysis. The study comprised 15,810 participants (mean age: 47.0 ± 15.7 years; 49.3% male). Multivariable Cox regression revealed that each DI-GM point rise correlated with 9% fewer premature deaths and 10% lower total mortality. Smooth curve fitting showed a clear inverse linear correlation between DI-GM scores and both premature and total mortality, consistent across subgroups. Mediation analysis revealed that biological age partially mediates this association. Elevated DI-GM scores were associated with a lower premature death and all-cause mortality, with biological aging serving as a significant mediator in this relationship.
Huang et al. (Thu,) studied this question.