Sample preparation and proteome analysis were performed as described previously11-13 Briefly, 51 saliva samples (17 samples before OFC, 17 samples 1 h after OFC, and 17 samples 2 h after OFC) were dissolved in 100 mM Tris-HCl (pH 8.0) containing 4% sodium dodecyl sulfate (SDS), 20 mM NaCl, and 10% acetonitrile (ACN) using a Bioruptor BR-II (SONIC BIO, Kanagawa, Japan). The extracted proteins (40 μg) were quantified using a Pierce™ BCA Protein Assay Kit (Thermo Fisher Scientific, Waltham, MA, USA) at 200 ng/μL. The protein extracts were reduced with 20 mM tris(2-carboxyethyl)phosphine for 10 min at 80 °C, followed by alkylation with 35 mM iodoacetamide for 30 min in the dark. Protein purification and digestion were performed using the SP3 method11. Tryptic digestion was performed using 500 ng/μL Trypsin platinum (Promega, Madison, WI, USA) overnight at 37 °C. The digests were purified using GL-Tip SDB (GL Sciences, Tokyo, Japan) according to the manufacturer’s protocol. The peptides were redissolved in decyl maltose neopentyl glycol (DMNG) containing 0.1% trifluoroacetic acid (TFA)12 and quantified using a BCA assay at 200 ng/μL.