It has been demonstrated that bacterial fractions of Lactobacillus gasseri with which humans have had dietary experience and which are therefore clearly safe for long-term intake 5 suppress delayed-type hypersensitivity reactions. Thus, the present invention provides agents containing bacterial fractions of Lactobacillus gasseri for alleviating delayed-type hypersensitivity. The present invention also provides food compositions containing bacterial fractions of Lactobacillus gasseri for alleviating delayed-type hypersensitivity. Furthermore, the present invention demonstrated that among such bacterial fractions, RNA fractions have a 10 particularly strong suppressive effect against delayed-type hypersensitivity reactions.
