The purpose of the present invention is to provide: a peptidoglycan recognition protein production promoter； or a composition for promoting the production of a peptidoglycan recognition protein. Preferred are: a peptidoglycan recognition protein production promoter which contains a bacterium belonging to the genus Bifidobacterium as an active ingredient； a composition (preferably a pharmaceutical composition, a food or beverage composition or a feed composition) for promoting the production of a peptidoglycan recognition protein, which contains a bacterium belonging to the genus Bifidobacterium； and a peptidoglycan recognition protein in a mucosal epithelial cell and/or a dendritic cell.本發明提供一種肽聚醣辨識蛋白質產生促進劑或肽聚醣辨識蛋白質產生促進用組成物。較佳為含有雙歧桿菌屬細菌作為有效成分之肽聚醣辨識蛋白質產生促進劑；含有雙歧桿菌屬細菌之肽聚醣辨識蛋白質產生促進用之組成物(較佳為醫藥組成物、飲食品組成物或飼料組成物)；黏膜上皮細胞及/或樹突狀細胞之肽聚醣辨識蛋白質。
