1. Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kida, Kagawa 761‑0793, Japan
2. Department of Gastroenterology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China
3. Life Science Research Center, Kagawa University, Kida, Kagawa 761‑0793, Japan