The dietary index for gut microbiota, genetically predicted gut microbiome, and the risk of chronic kidney disease: a cohort study

Abstract

Background: The dietary index for gut microbiota (DI-GM) is a recently proposed index that reflects the diversity of the gut microbiota from the perspective of dietary intake. However, its association with chronic kidney disease (CKD) has not been widely studied. Methods: This prospective cohort study included 166,865 participants free of CKD at baseline. DI-GM was assessed through a 24-h dietary recall questionnaire. Incident CKD was ascertained using hospital inpatient records, death registry data, and primary care data. A genetic risk score for gut microbial abundance was constructed based on 19 variants. Cox proportional hazards model was used to estimate hazard ratio (HR) and 95% confidence interval (CI) for CKD incidence. Results: During a median follow-up of 9.44 years, 3,977 participants developed CKD. In the fully adjusted model, compared with the lowest group for the DI-GM (0-3 points), participants in higher DI-GM groups (4, 5, and ≥ 6 points) had a significantly lower risk of CKD. The adjusted HRs (95% CIs) for these groups were 0.81 (0.74, 0.88), 0.79 (0.72, 0.86), and 0.73 (0.67, 0.80), respectively (P for trend < 0.0001). Significant multiplicative interactions were observed between genetically predicted gut microbial abundance and adherence to the DI-GM (P for interaction = 0.004). Conclusion: Adherence to the DI-GM was strongly linked to a reduced risk of incident CKD, particularly in individuals with high gut microbial abundance.