PROBLEM TO BE SOLVED: To provide a novel use method for Myctophidae fish and a novel DPP-IV inhibitor.SOLUTION: The present invention relates to a composition obtained by treating fish bodies and/or fish meal with protease, the composition comprising L-R of 10 μg/kg or more.SELECTED DRAWING: Figure 2COPYRIGHT: (C)2017,JPO&INPIT【課題】ハダカイワシの新規な利用法および新規DPP-IV阻害剤を提供する。【解決手段】魚体および/または魚粉をタンパク質分解酵素で処理して得られる組成物であって、L-Rを10μg/kg以上含有する組成物。【選択図】図2