3 food pellets were collected.  DNA was extracted using the DNeasy¨ Blood and Tissue Kit from QIAGEN according to the manufacturer's instructions.  The DNA was amplified by PCR using the primers S-D-Arch-0519-a-S-15  (5ÕCAGCMGCCGCGGTAA-3' ) and S-D-Bact-0785-b-A-18 (5Õ-TACNVGGGTATCTAATCC-3Õ ) specific to region V4 of rRNA 16S. We used the TaKaRa Premixª 2.0 to perform the PCR according to the manufacturer's instructions. DNA concentration was quantified on Nanodrop. The sequencing was done on Illumina MiSeq.