Soy peptides ameliorate the progression of chronic kidney disease in mice via inhibition of inflammation

For patients with chronic kidney disease (CKD), adequate protein intake is required to cope with proteinuria-induced protein loss, but excessive protein consumption may increase renal pressure and exacerbate kidney injury. In contrast to macromolecular proteins, peptides with high tissue permeability and biological activity can efficiently serve as protein sources without exerting glomerular pressure. To investigate the potential of peptides as nutritional intervention in CKD, we initially optimized CKD mouse model by treating with 75 mg/kg/day adenine for up to 21 days. Subsequently, we confirmed that peptides exhibited higher increase in survival rate of CKD mice compared to proteins, possibly due to their relatively high oligopeptide levels of 64.5%. Additionally, compared to positive control group, the soy peptides replacement feed significantly reduced serum urea nitrogen levels (15.4%, P < 0.05) and notably decreased the cross-sectional area of renal tubules (13.1%, P < 0.05) as observed through HE staining. The findings further indicated that soy peptides ameliorated kidney damage by inhibiting inflammatory factors TNF-α and IL-6 expression. Combined with peptides composition analysis, soy peptides were shown to aid in regulating the acid-base balance in mice with CKD. In summary, this study evidenced that soy peptides are viable protein source for nutritional intervention to ameliorate the progression of CKD.