Global profiling of metabolites from saliva of tobacco consumers
The long-term health effects associated with cigarette smoking have been shown to be more harmful compared to those associated with the consumption of non-combustible tobacco products, such as moist snuff. In order to investigate the long-term health effects of tobacco exposure, we evaluated the saliva metabolomic profiles of 40 smokers (SMK), 40 moist snuff consumers (MSC), and 40 non-tobacco consumers (NTC) using UHPLC-mass spectrometry based metabolomic profiling. Saliva samples were collected from adult male subjects who abstained overnight from both food and tobacco. Metabolomic profiling and data analyses performed at Metabolon, Inc, (Durham NC) indicate that a total of 407 biochemicals (310 known and 97 unnamed metabolites) were detected. While the known metabolites included three biochemicals from nicotine metabolism, the rest of them belonged to diverse metabolic pathways.
Smokers exhibited a larger number of statistical (p<0.05) differences relative to the non-smoking groups. For example, 94 metabolites were significantly different in SMK compared to NTC, 91 changes were detected in SMK versus MSC and 46 biochemicals were different between MSC and NTC. These biochemicals fit into distinct metabolic pathways such as oxidative stress, inflammation, macromolecular rearrangement/tissue remodeling, xenobiotic biochemistry, amino acid, cellular energetics and microbial metabolism. Random Forest analyses revealed that SMK profiles were distinct from the MSC and NTC cohorts, while MSC profiles showed more subtle changes and were difficult to distinguish from NTC. In summary, these data present changes in global saliva biochemical profiles in generally healthy cigarette smokers and moist snuff consumers. These differences in the metabolite profiles may be useful in understanding the relative risks associated with smoking compared to consumption of smokeless tobacco products.