Restrictive diets have a beneficial impact on DSS-induced colitis in male mice

Previously, we assessed the impact of restrictive diets, including caloric restriction (CR), intermittent fasting (IF), or fasting-mimicking diet (FMD), on a healthy gastrointestinal tract. We revealed that each of the diets shows anti-inflammatory outcomes. The current study aimed to verify the diets' applicability in treating colitis. We exposed a mouse model with mild chronic DSS colitis to ad libitum control feeding, CR, IF, or FMD. The collected samples were analyzed for markers of inflammation. The diets reduced DSS-triggered increases in spleen weight and myeloperoxidase (MPO) activity. Diet intervention also influenced occludin levels, small intestine morphology, as well as cytokine and inflammatory gene expression, mainly in the mucosa of the proximal colon. The diets did not reverse DSS-enhanced gut permeability and thickening of the colon muscularis externa. Concerning inflammatory gene expression, the impact of DSS and the dietary intervention was limited to the colon as we did not measure major changes in the jejunum mucosa, Peyer's patches, and mesenteric lymph nodes. Further, rather modest changes in the concentration of intestinal bile acids were observed in response to the diets, while taurine and its conjugates levels were strongly affected. Despite the differences in the dietary protocol, the tested diets showed very similar impacts and, therefore, may be interchangeable when aiming to reduce inflammation in the colon. However, FMD showed the most consistent beneficial impact.