Clam Peptides Attenuated Adenine-Induced Chronic Kidney Disease by Improving Inflammation, Oxidative Stress, and Intestinal Flora Composition

Previously, we have prepared clam peptides (RBPs) that exhibited potential antihypertension and kidney protective effects in SHR rats by fermentation of Ruditapes philippinarum with Bacillus natto. In this study, we established an adenine-induced chronic kidney disease (CKD) in SD rats and investigated the improvement effects of RBPs on CKD. The results showed that compared with the model group, 8 weeks gavage of RBPs restored the structure of the kidney and reduced serum levels of CKD-related biochemical indicators, including NGAL, CR, Ca, UA, TG, IP, L-FABP, BUN, CHO, and cystatin C (p<0.05). RBPs treatment also reduced serum levels of MDA, IL-1 beta, TGF-beta 1, and TNF-alpha and increased those of CAT and T-AOC (p<0.05). In addition, the results of intestinal microbiota analysis showed that RBPs improved the intestinal flora composition by downregulating the proportion of Firmicutes and Bacteroidetes, decreasing the relative abundance of Romboutsia, Ruminococcaceae_UCG-005, and Christensenellaceae_R-7_group and increasing that of Lactobacillus and Muribaculaceae (p<0.05). The results of this study indicated that RBPs can also be used as bioactive substances in marine drugs or functional foods to alleviate CKD.