Associations of Microbiota-Friendly Diet with Risk of Diabetic Retinopathy in NHANES: Mediating Role of Oxidative Stress and Inflammation.

PURPOSE: Growing evidence implicates gut microbiota dysbiosis in the pathogenesis of diabetic retinopathy (DR). This study aimed to investigate the associations between dietary index for gut microbiota (DI-GM), a novel metric reflecting gut microbiota composition and diversity, and DR risk, as well as to examine the mediating role of inflammatory and oxidative stress biomarkers.

METHODS

This cross-sectional study analyzed 4,003 diabetic individuals (mean age 59 years, 51.21% men) from 1999-2018 National Health and Nutrition Examination Survey. DI-GM was derived from self-reported 24-hour dietary recalls. Mediation analysis was used to investigate the role of inflammation (neutrophils, lymphocytes, and alkaline phosphatase) and oxidative stress (gamma-glutamyl transferase, uric acid, and total bilirubin) biomarkers in the effects of DI-GM on DR prevalence. Binary logistic regression analysis was adopted to explore the association of DI-GM and DR prevalence.

RESULTS

The prevalence of DR was 19.64%. Multivariate-adjusted odds ratio (95% confidence intervals) for the association between DI-GM and DR prevalence was 0.73 (0.68-0.79). Restricted cubic spline curves showed a non-linear inverse relationship between DI-GM and DR prevalence. Subgroup analysis indicated that the association between DI-GM and DR prevalence was more pronounced in participants with a body mass index > 25 kg/m2. Alkaline phosphatase and total bilirubin mediated 10.27% and 9.45% of the effects of DI-GM scores on DR prevalence.

CONCLUSIONS

Adherence to microbiota-friendly diet was associated with a lower DR prevalence, especially among individuals with overweight or obesity. Alkaline phosphatase and total bilirubin may be associated with the gut microbiota-retina interactions in DR.