Oral microbiome: Sample CN00032626
The hypervariable V3-V4 region of the bacterial 16S rRNA gene was amplified using the universal primers 341F (5-CCTACGGGNGGCWGCAG-3) and 805R (5-GGACTACHVGGGTATCTAATCC-3). Library preparation consisted of a first PCR to amplify the target region followed by a second PCR to attach sample-specific indices. The resulting libraries were purified and assessed using the QIAxcel Advanced System (Qiagen, Germany) to verify fragment size and library quality prior to sequencing. Sequencing was performed on an Illumina MiSeq platform using paired-end reads (2  250 bp) and sequencing-by-synthesis chemistry. Raw sequencing data were generated in FASTQ format for downstream bioinformatic analysis.