design: Whole cecum samples from the adult rats were collected during sacrifice, flash frozen on dry ice, and stored at -80C until further processing. To obtain cecum contents, approximately 150 mg of contents were removed from the cecum lining using sterilized forceps while working on dry ice. DNA was extracted using the QIAamp Fast DNA Stool Mini Kit. Samples were diluted in molecular-grade water to a final concentration of 25 ng/L and stored at -20C before undergoing the 16S rRNA gene amplicon sequencing. The V3-V4 region of the 16S rRNA gene was amplified with specific primers for this region. Diluted pooled samples were sequenced with the 500-cycle MiSeq Reagent Kit v3 protocol on the MiSeq System by Illumina.