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-1　(IL-1),　interleukin-6　(IL-6),　and　tumor　necrosis　factor-　(TNF-)　in　the　colon,　rather　than　in　peripheral　blood.　Glycine　and　Pro-Hyp　attenuated　the　DSS-induced　rise　in　colonic　IL-6　and　TNF-,　as　well　as　peripheral　IL-1,　IL-6,　and　TNF-.　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.