Modulation of Inflammation Levels and the Gut Microbiota in Mice with DSS-Induced Colitis by a Balanced Vegetable Protein Diet

Inflammatory bowel disease (IBD) is a nonspecific chronic inflammatory disease of the intestine that is mainly divided into ulcerative colitis and Crohn's disease. Nutrients play important roles in the treatment of IBD. In this study, the effects of vegetable proteins on the regulation of IBD were explored via the amino acid scoring formula. Two diets with different amino acid scores, a balanced one and an imbalanced one, were assessed for their effects on acute colitis induced by dextran sodium sulfate (DSS). Pathological symptoms were evaluated by the disease activity index (DAI) and hematoxylin-eosin (H&E) staining, the expression of inflammatory factors and barrier proteins was determined via qPCR and western blotting, and the intestinal microbiota was examined via 16 S rRNA sequencing. The results indicated that the balanced vegetable protein diet (BVPD) relieved colitis by reducing the colonic histological score, inhibiting the expression of proinflammatory factors such as IL-1 beta, IL-6, and TNF-alpha and promoting the expression of tight junction proteins. Analysis of gut microbes revealed that the BVPD altered the structural composition of the intestinal flora in animals with DSS-induced colitis by increasing the abundance of beneficial bacteria (Lactobacillus, Bifidobacterium, etc.). In conclusion, a BVPD effectively relieves colitis and may be a promising adjuvant strategy for the treatment of IBD.