metagenome of mus musculus feces
Bacteria were obtained from the teeth and gingival surface by swab collection and bacteria were eluted in PBS in cell lysis buffer from a DNeasy kit (Qiagen, Valencia, CA, USA) as described (Grice et al., 2010a). After a 60-s vortex, DNA present in the buffer was isolated with the DNeasy kit and quantitated with a spectrophotometer (Tecan, Mannedorf, Switzerland). 515F/806R primer with golay barcode in the reverse primer was used to amplify the V4 region of 16S ribosomal DNA (16S rDNA; IDT, Coralville, IA, USA) following the procedure described by Grice et al to obtain bacteria from db/db diabetic mice (Grice et al., 2010a). PCR was performed in 50-uL reactions and then purified with both Agencourt XP DNA purification beads (Beckman Coulter, Beverly, MA, USA) and QiaAmp DNA Mini Spin Columns (Qiagen).