<;P>;PROBLEM TO BE SOLVED: To provide a new lactic bacterium strain having immunostimulating activity and gastric juice resistance, to provide an immunostimulating composition containing the new lactic bacterium strain, and to provide a food and drink and a medicine containing the immunostimulating composition. <;P>;SOLUTION: The new lactic bacterium having the immunostimulating activity and the gastric juice resistance is lactic bacterium Pediococcus sp. KB1 (NITE P-755). The food and drink, the medicine and the like having the immunostimulating activity contain the lactic bacterium Pediococcus sp. KB1 (NITE P-755) as an active ingredient. <;P>;COPYRIGHT: (C)2011,JPO&INPIT