The present invention provides a probiotics product comprising, as an effective component, lactic acid bacteria belonging to Lactobacillus salivarius possessing high adhesiveness to mucous membrane, a high proliferation ability and a high resistance to acids, a composition for preventing and/or treating digestive tract's diseases comprising the probiotics product as an effective component and a novel Lactobacillus salivarius strain possessing high adhesiveness to mucous membrane, a high proliferation ability and a high resistance to acids. The lactic acid bacteria and the probiotics product and the composition for preventing and/or treating digestive tract's diseases, which contain the lactic acid bacteria as an effective component, according to the present invention can sufficiently show their probiotics functions without being easily discharged from the digestive tract and urinogenital organs.