1. Department of Gastroenterology; Sir Run Run Shaw Hospital; Zhejiang University Medical School; Hangzhou China
2. Institute of Gastroenterology; Zhejiang University (IGZJU); Hangzhou China
3. Department of Microbiology; Tumor and Cell Biology; Karolinska Institute; 171 77 Stockholm Sweden
4. State Key Laboratory for Diagnosis and Treatment of Infectious Diseases; The First Affiliated Hospital; School of Medicine; Zhejiang University; Hangzhou China