Abstract

Abstract Gelatin is an anti‐inflammatory dietary component, and its predominant metabolites entering circulation are prolyl‐hydroxyproline (Pro‐Hyp) and glycine. We evaluated the protective effects of orally administered gelatin, glycine, and Pro‐Hyp 10:3:0.8 (w/w/w) against dextran sodium sulfate (DSS)‐induced colitis in mice. According to clinical, histological, and biochemical parameters, they exhibited significant activities in the order of gelatin < glycine < Pro‐Hyp. Gelatin prevented the DSS‐induced increase in interleukin‐1β (IL‐1β), interleukin‐6 (IL‐6), and tumor necrosis factor‐α (TNF‐α) in the colon, rather than in peripheral blood. Glycine and Pro‐Hyp attenuated the DSS‐induced rise in colonic IL‐6 and TNF‐α, as well as peripheral IL‐1β, IL‐6, and TNF‐α. Hematologic results show the attenuation of DSS‐induced leukocytosis and lymphocytosis by glycine and Pro‐Hyp, rather than gelatin. These findings suggest that glycine and Pro‐Hyp constitute the material basis for gelatin's anticolitis efficacy, and they have better anticolitis activities and distinct mechanisms of action when ingested as free compounds than as part of gelatin.