The present invention pertains to a composition for improving intestinal barrier function, the composition containing a compound comprising a gallic acid residue as an active ingredient, the compound comprising a gallic acid residue being one or more substances selected from the group consisting of (A1) through (A3). (A1) A flavan-3-ol polymer comprising a galloyl group； (A2) a hydrolyzable tannin； (A3) one or more compounds selected from the group consisting of catechin gallate, epicatechin gallate, and gallocatechin gallate.
