1. Division of Genome-Wide Infectious Diseases, Research Center for GLOBAL and LOCAL Infectious Disease, Oita University, Yufu, Japan
2. Department of Gastroenterology, National Hospital Organization Kyoto Medical Center, Kyoto, Japan
3. Department of Gastroenterology, Oita University, Yufu, Japan
4. Department of Environmental and Preventive Medicine, Oita University, Yufu, Japan
5. Department of Gastroenterological Endoscopy, Tokyo Medical University Hospital, Shinjuku, Japan