1. Research Group of Gastrointestinal Diseases, the Second Affiliated Hospital, Zhengzhou University, Zhengzhou, China.
2. The Academy of Medical Science, Zhengzhou University, Zhengzhou, China.
3. Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway.
4. Faculty of Health Science, Nord University, Campus Levanger, Levanger, Norway.