Disclosed is a composition comprising at least one Gram-positive bacterium isolated from the intestine of an animal including human or a fermented food as an active ingredient. The composition can be used for inhibition or reduction of in vivo proliferation of Mycobacterium leprae. The composition can be used for prevention, progression prevention or amelioration of Hansen's disease or a condition associated with Hansen's disease. The composition can be ingested readily in a daily life, is safe, and develops reduced adverse side effects.
