1. Division of Gastroenterology and Hepatology, Department of Internal Medicine, The Jikei University School of Medicine, Kashiwa Hospital, Chiba, Japan;
2. Department of Public Health and Environmental Medicine, The Jikei University School of Medicine, Tokyo, Japan;
3. Institute of Clinical Medicine and Research, The Jikei University School of Medicine, Chiba, Japan;
4. Division of Gastroenterology and Hepatology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan;
5. Department of Oral Medicine and Stomatology, Tsurumi University School of Dental Medicine, Kanagawa, Japan;
6. Department of Surgery, The Jikei University School of Medicine, Kashiwa Hospital, Chiba, Japan;
7. Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Osaka, Japan