Histological assessment
The isolated colon tissues were fixed in 10% formalin for one week, embedded in paraffin, and sectioned into 5 µm slices, and then the sections were stained with hematoxylin-eosin (H&E) solution. Finally, images of the stained sections were photographed using a light microscope (Nikon Eclipse TE2000-U, NIKON, Japan) at 200 × magnification.