Milk reduces severity of dextran sulfate sodium induced colitis in rats

Introduction: Ulcerative colitis (UC) is characterized by chronic inflammation and persistent diarrhea and hemorrhage. The aim of this study was to compare the effects of whole milk, skim milk, and whey powder supplementation on disease activity and colonic inflammation in rat UC models. Materials and methods: Wistar:slc rats were divided into four groups according to their diets: (1) AIN-93G (Control), (2) 20% milk to AIN-93G (Milk), (3) 20% skim milk to AIN-93G (S-Milk), (4) 20% whey to AIN-93G (Whey). All rats developed experimental UC by drinking 3% dextran sulfate sodium for 10 days. The body weight and disease activity index (DAI) scores were estimated every day. Hematoxylin and eosin (H&E) staining, histological assessment (HIS), and immunostaining of neutrophil elastase (NE) were performed on their colon tissues. Some inflammatory markers in their serum and colon tissues were also measured. Results: The primary outcomes (DAI and HIS) indicated that whole milk intake was associated with milder colitis, whereas whey showed higher DAI and skim milk showed higher HIS. Secondary endpoints showed that colon length did not differ significantly among groups, and terminal-time-point cytokines showed modest, non-significant differences. Conclusions: Since milk is the most effective dairy product in improving the pathogenesis of UC, it would be necessary to investigate which components of it are particularly beneficial in the future.