Longitudinal characterization of maternal and infant salivary proteomic profiles across pregnancy and early infancy

Abstract Background Pregnancy and infancy are critical stages for health intervention and physiological change. Although salivary proteomic shifts have been reported in pregnant women and infants, simultaneous mother-infant profiling—particularly using mass spectrometry—remains unexplored. Objective To investigate the salivary proteomic profile in the mother-baby dyad, considering the third trimester of pregnancy. Materials and methods Twenty pregnant women (PW) in the last trimester were selected and followed up. The PW were examined to assess caries experience (DMFT) and periodontal condition (CPI). Income, education, body mass index (BMI), and dietary practices were assessed through a questionnaire. Saliva samples were collected during pregnancy and postpartum (PP), as well as from the one-month infants (IF), and analyzed using mass spectrometry. Data were evaluated by descriptive statistics and bioinformatics. Results PW in the study were from mid-level socioeconomic backgrounds with a high prevalence of caries (80%) and periodontal changes (60%). The average BMI was 28.37 kg/m 2 in pre-pregnancy, indicating an overweight status, and the mean weight gain by the 3rd trimester was 7.23 kg. 35–40% of PW reported high consumption of carbohydrate. Proteomic analysis qualitatively identified 21, 27, and 25 proteins in PW, PP, and IF, respectively, with five proteins common to all groups. Key protein interactions were observed for salivary amylase (AMY1A, AMY1B, AMY1C), which are supposed to be linked to overweight. Gene Ontology (GO) enrichment analysis identified common genes and functional attributes across groups, with variation in expression intensity. Under GO molecular function, similarities were restricted to the PW and PP groups—specifically regarding alpha amylase activity and calcium, chloride, metal and antigen ion binding. Conversely, GO biological process analysis demonstrated that oligosaccharide metabolism was conserved across all groups (PW, PP, and IF). Conclusion The salivary proteomic profiles of PW, PP, and IF shared several qualitatively identified proteins and showed notable similarities, suggesting candidates for further evaluation in maternal and neonatal health.