1. Department of Surgery, Graduate School of Medicine Kyoto University Kyoto Japan
2. Department of Hepato‐Biliary‐Pancreatic Surgery and Transplantation Kanazawa University Ishikawa Japan
3. Department of Biomedical Statistics and Bioinformatics, Graduate School of Medicine Kyoto University Kyoto Japan
4. Yakult Central Institute Yakult Honsha Co. Ltd. Tokyo Japan
5. Shiga University of Medical Science Shiga Japan