Saliva sampling and analyses
The examiner collected unstimulated whole saliva samples at baseline and after 8 days before the biofilm scoring. The subjects rinsed with tap water, accumulated saliva in their mouth and expectorated in a capped plastic tube (approximately 1.0 ml). The tube was immediately frozen and stored at −18°C until transportation and further processing at the Novozymes A/S laboratory in Denmark. We included negative control samples (no material/DNA) as well as positive controls consisting of a known mock community to validate the analyses. The DNA extraction was performed with Macherey-Nagel™ NucleoSpin™ Soil kit and the V3–V4 region of 16S rRNA gene was PCR amplified using universal primers. The amplicons were sequenced using Illumina MiSeq 300 bp paired end. We provide a full description in 