The relationship between dietary index for gut microbiota and diabetes

This study aims to explore the relationship between the Dietary Index for Gut Microbiota (DI-GM) and diabetes. In recent years, there has been increasing attention to the role of the gut microbiome in regulating host metabolism. However, the relationship between DI-GM and the risk of diabetes has not been sufficiently studied. This study utilized relevant data from the National Health and Nutrition Examination Survey (NHANES) 2007-2018. Multiple logistic regression analysis was conducted to explore the relationship between DI-GM and the risk of diabetes. The dose-response relationship between DI-GM and the risk of diabetes was observed using restricted cubic splines (RCS). Threshold effect analysis was performed based on RCS results. Subgroup analyses were used to conduct a sensitivity analysis of the relationship between DI-GM and the risk of diabetes. The results from multiple logistic regression analysis indicated a significant negative correlation between DI-GM and the risk of diabetes (OR, 0.954, 95%CI, 0.918-0.991). RCS results also showed a significant nonlinear negative relationship between DI-GM and the risk of diabetes (P < 0.001, P for nonlinear = 0.010). The threshold effect analysis revealed that when DI-GM was below 6.191, there was a significant negative correlation between DI-GM and the risk of diabetes (OR, 0.921, 95% CI, 0.876-0.969). However, when DI-GM exceeded 6.191, the relationship between DI-GM and the risk of diabetes was no longer significant. Subgroup analysis revealed that the negative correlation between DI-GM and the risk of diabetes remained significant in Whites, participants with a poverty-income ratio > 3.5, body mass index > 24, current drinkers, never or current smokers, and those without chronic kidney disease (P < 0.05). This study demonstrates a nonlinear negative correlation between DI-GM and the risk of diabetes. Maintaining DI-GM above 6.191 may help prevent diabetes.