PROBLEM TO BE SOLVED: To provide a new lactic acid bacterium, and a medicine, a food and drink and a fodder, containing the new lactic acid bacterium, and to provide a means effective for antimicrobe, antiinflammatory, antitumor and immunosuppression.SOLUTION: The new lactic acid bacterium is Lactobacillus gasseri MCC1183 strain (accession number: FERM P-21908). The medicine, the food and drink and the fodder contain the Lactobacillus gasseri MCC1183 strain. The antimicrobial agent, the antiinflammatory agent, the antitumor agent and the immunosuppressant contain the Lactobacillus gasseri MCC1183 strain.