1. Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Guangdong Institute of Gastroenterology, The Sixth Affiliated Hospital, Sun Yat‑sen University, Guangzhou, Guangdong 510655, P.R. China
2. Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat‑sen University, Guangzhou, Guangdong 510000, P.R. China
3. Institute of Nutrition and Food Safety, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, Guangdong 511430, P.R. China