PROBLEM TO BE SOLVED: To provide a new strain which is high in an ability for inducing the production of cytokine, interleukin-10 (IL-10) having an action for inhibiting the exasperation of immunocompetence in inflammatory diseases or allergic diseases and is useful for preventing and treating diseases caused by the shortage in the production of IL-10.SOLUTION: There are provided a Lactobacillus pentosus TJ515 (FERM P-21798) strain; the dry powder and culture product of the strain; and a food and a medicine containing the same.