KL and renal fibrosis: Furthermore, Spearman’s correlation analysis was performed to correlate the composition of the gut microbial communities with biochemical indexes (UA and CR), kidney injury markers (Kim-1, NGAL, and klotho), renal fibrosis biomarkers (TGF-β1, Fibronectin and Collagen I), oxidative stress markers (MDA, GSH, and SOD), and fecal SCFAs concentration.