Oral Mouthwash and Cytobrush Sampling Protocol

Self‐collected oral mouthwash samples were collected using the NHANES methodology (Gillison et al., 2012 (link)). A 50‐ml sterile collection cup filled with 10 ml of Scope (original mint flavor) was provided to each participant. They were asked to rinse/gargle with the mouthwash for 30 seconds, spit the mouthwash into the collection cup while trying not to spill the liquid, and close the cup tightly. Afterward, participants used a cytobrush (QIAGEN) to self‐collect an oral sample (Read et al., 2012 (link)). They gently brushed the gums' inner and outer areas for at least 10 strokes. Samples were obtained using the digeneHc2 DNA collection device from QIAGEN. Both samples were performed during the visit and supervised by the study coordinators.