1. Department of Colorectal Surgery, The Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
2. Department of General Surgery, The Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
3. Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, Guangdong Institute of Gastroenterology, the Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China
4. Key Laboratory of Human Microbiome and Elderly Chronic Diseases, Ministry of Education, Guangzhou, Guangdong, China
5. School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China