1. Second School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong, China
2. First School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong, China
3. Department of Gastroenterology, South China University of Technology, Guangzhou, Guangdong, China
4. Guangdong Geriatrics Institute, Guangdong Provincial People’s Hospital and Guangdong Academy of Medical Sciences, South China University of Technology, Guangzhou, Guangdong, China