Acknowledgements
We thank all participating patients and their families, as well as the additional investigators, Dr. Kazunaga Ishigaki and Dr. Kei Saito from Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Dr. Shinichiro Yamada from Department of Surgery, Tokushima University Graduate School of Biomedical Sciences, and research coordinators and the members from WDB clinical research Co., Ltd. and Clinical Research Promotion Center, The University of Tokyo Hospital for the study management.