Intestinal Morphology Measurement Protocol

The procedure of preparing samples for measuring intestinal morphology was performed as described previously (Wu et al., 2018 (link)). Briefly, the samples were dehydrated and embedded in paraffin, sectioned at a thickness of 4 mm, and stained with haematoxylin and eosin. Morphological examination was conducted with a light microscope (Leica microsystems, Wetzlar, Germany) with the Leica Application Suite image analysis software (Leica microsystems, Wetzlar, Germany). Eight areas per slide were inspected randomly in a double-blind manner. Intestinal villus height and crypt depth were measured to calculate the ratio of villus height to crypt depth.