Association between the gut microbiota and diabetic nephropathy: a two-sample Mendelian randomization study.

Numerous studies have revealed a correlation between the risk of developing diabetic nephropathy (DN) and the gut microbiota (GM) composition. However, it remains uncertain whether the GM composition causes DN. We aimed to explore any potential causal links between the GM composition and the risk of developing DN. A meta-analysis conducted by the MiBioGen consortium of the largest genome-wide association study (GWAS) provided aggregated data on the GM. DN data were obtained from the IEU database. The inverse-variance weighting (IVW) method was employed as the primary analytical approach. The IVW analysis indicated that genus (OR = 0.51, 95% CI: 0.34-0.77,  = 0.00118) was protective against DN. In addition, class (OR = 0.47, 95% CI: 0.27-0.83,  = 0.0096), class (OR =0.76, 95% CI: 0.68-0.99,  = 0.04), order (OR = 0.76, 95% CI: 0.58-0.99,  = 0.04), and phylum (OR = 0.53, 95% CI: 0.33-0.85,  = 0.00872) were negatively associated with the risk of developing DN. Genus (OR =1.45, 95% CI: 1.08-1.95,  = 0.01), order (OR = 1.59, 95% CI: 1.02-2.49,  = 0.04), and genus (OR = 1.98, 95% CI: 1.14-3.45,  = 0.015) were positively associated with the risk of developing DN. In this study, we established a causal relationship between the genus and the risk of developing DN. Further trials are required to confirm the protective effects of probiotics on DN and to elucidate the precise protective mechanisms involving genus and DN.