1. Department of Gastroenterology and Hepatology, Yokohama City University School of Medicine, Yokohama, Japan
2. R&D Center, Biofermin Pharmaceutical Co., Ltd., Kobe, Japan
3. Department of Gastroenterology, International University of Health and Welfare Atami Hospital, Atami, Japan
4. Department of Pathology, Yokohama City University Hospital, Yokohama, Japan
5. Department of Pharmacology, Faculty of Medicine, Shimane University, Izumo, Japan