1. Division of Gastroenterology, Department of Medicine, Faculty of Medicine Siriraj Hospital Mahidol University Bangkok Thailand
2. Department of Research and Development, Faculty of Medicine Siriraj Hospital Mahidol University Bangkok Thailand
3. Division of Gastroenterology, Department of Medicine, Panyananthaphikkhu Chonprathan Medical Center Srinakharinwirot University Nonthaburi Thailand
4. Division of Endocrinology and Metabolism, Department of Medicine, Faculty of Medicine Thammasat University Rangsit Thailand