Disclosed are a composition having an anti-inflammatory function and a therapeutic method using the composition, both of which are effective for inflammatory diseases such as inflammatory bowel disease. Specifically disclosed are: an anti-inflammatory functional agent for oral application, which comprises a soybean peptide, wherein the soybean peptide contains fractions each having a molecular weight of 500 or less and excluding any free amino acid in an amount of 40 wt % or more and has a free amino acid content of 7 wt % or less； and a therapeutic method using the anti-inflammatory functional agent. More specifically disclosed are: a novel tripeptide which comprises the following amino acid sequence: phenylalanine-leucine-valine or valine-proline-tyrosine and has an anti-inflammatory function； an anti-inflammatory composition for oral application, a medicinal agent and a feed, each of which contains the novel tripeptide as an active ingredient； and a method for treating inflammatory bowel disease using the novel peptide.
