1 Department of Gastroenterology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, Guangzhou, China.
2 The Second School of Clinical Medicine, Southern Medical University, Guangzhou, China.
3 Shantou University Medical College, Shantou University, Shantou, China.
4 Department of Computer Science, The University of Hong Kong, Hong Kong, Hong Kong SAR, China.
5 Sepulveda Ambulatory Care Center, VA Greater Los Angeles Healthcare System, Los Angeles, CA, United States.
6 University of California Los Angeles David Geffen School of Medicine, Los Angeles, CA, United States.