This composition, which contains, as active ingredients, microbial cells of a lactobacilli belonging to Lactobacillus paracasei, a cultured product or fermented product thereof, or a polysaccharide produced by the same, is effective for preventing or alleviating type I allergy. In particular, this composition can be used as food, medication, animal food, and cosmetics for preventing or alleviating anaphylaxis.
