Salivary biomarkers associated with perceived satiety and body mass in humans

Regulation of food intake and energy homeostasis is controlled by a delicate balancing of numerous central and peripheral factors, including circulating peptide hormones. This study investigated the proteome of saliva using SELDI-TOF-MS in relation to satiety and body mass index (BMI) in humans. Within a longitudinal test session, 18 subjects were exposed to a lunch-induced hunger-satiety shift, while every 15 min collecting their whole saliva and rating their hunger and satiety. Saliva was analysed by SELDI-TOF-MS using IMAC arrays with a chromatographic copper surface (IMAC-Cu). From all subjects and time points measured, peptide and protein profiles showed 190 common peaks. Their interrelationships show that 37% of the variation was accounted for in one dimension. About 30 means had a strong association (0.70<|r|<0.95) with all subjective satiety ratings across time during the test session, and seven peaks were significantly correlated to BMI. Database MS searches indicated characterisation of some relevant metabolic peptide hormones. In conclusion, SELDI-TOF-MS on human saliva provides a valuable and noninvasive way of profiling that enables characterisation of novel and differently expressed peptides and proteins which can be used as biomarkers of satiety and overweight.