title: 16S rRNA sequencing of the oral Microbiome of smokers
design: In brief, participants were asked to fast for 9 hours prior to oral rinse and blood specimen collection. A 20-second oral rinse was divided into two 5-second swish and 5-second gargle sessions using 15 mLs of Scope mouthwash, which was transported on dry ice and stored at -80C. A modified protocol of the QIAamp DNA mini kit (QIAGEN) was used for DNA extraction. DNA was amplified for the V4 variable region of the 16S rRNA gene. High-throughput amplicon sequencing was conducted on a MiSeq (Illumina, San Diego, CA) using 2x300 paired-end fragments.