1 State Key Laboratory of Cancer Biology, National Clinical Research Center for Digestive Diseases, Xijing Hospital, Air Force Medical University, Xi'an, Shaanxi 710032, China.
2 Department of Gastroenterology, Chinese Armed Police Force Fujian Armed Police Corps Hospital, Fuzhou, Fujian 350001, China.
3 Department of Clinical Nutrition, Xijing Hospital, Air Force Medical University, Xi'an, Shaanxi 710032, China.
4 Department of Radiation Protective Medicine, Air Force Medical University, Xi'an, Shaanxi 710032, China.