2.1. Ethical statement
The research protocol was reviewed and approved by the Research Ethics
Committee and the Animal Ethical Committee of Hainan Medical University.
All wild rats were captured with traps and killed by CO2inhalation. Fecal samples were collected from other rodent farms with
the consent of farm owners. During the experimental process, all animals
were handled and cared for according to the Chinese Laboratory Animal
Administration Act of 1998.