design: DNA from cecal contents was extracted using the Zymo Research Fecal DNA kit and amplified with primers targeting the V3-V4 region of the 16S rRNA gene. The amplicons generated were pooled and purified using the Qiagen Gel Extraction Kit (Qiagen, Germany). The amplicons were pooled, purified, and sequenced on an Illumina MiSeq system. MiSeq data were assembled with "pear" software, aligned to the SILVA database, and processed using the mothur pipeline. Taxonomic classification was performed using the Ribosomal Database Project, and nonbacterial sequences were removed. OTUs were calculated at a 0.03 distance using mothur, and microbial communities were analyzed with UniFrac Principal Coordinates Analysis (PCoA).