1. Department of Gastroenterology, West China School of Public Health and West China Forth Hospital, Sichuan University, Chengdu, China
2. Non-communicable Diseases Research Center, West China-PUMC C. C. Chen Institute of Health, Sichuan University, Chengdu, China
3. Department of Pathology, West China School of Public Health and West China Forth Hospital, Sichuan University, Chengdu China