PROBLEM TO BE SOLVED: To provide a Bacillus which can reduce serotonin in the intestine.SOLUTION: This bacillus has serotonin-metabolic capacity during proliferation, and its spore has abilities to tolerate low pH and bile acid.【課題】腸管内のセロトニンを低減できるバチルス属菌の提供。【解決手段】芽胞が低pH耐性能及び胆汁酸耐性能を有し、かつ増殖時にセロトニン代謝能を有するバチルス属菌。【選択図】なし