1. Division of Gastroenterology; Department of Internal Medicine; Kobe University Graduate School of Medicine; 7-5-1 Kusunoki-Cho, Chu-o-ku; Kobe; Hyogo; 650-0017; Japan
2. The Integrated Center for Mass Spectrometry; Kobe University Graduate School of Medicine; 7-5-1 Kusunoki-Cho, Chu-o-ku; Kobe; Hyogo; 650-0017; Japan
3. Department of Biotechnology; Graduate School of Engineering, Osaka University; 2-1 Yamadaoka; Suita; Osaka; 565-0871; Japan