VOC Profiles of Saliva in Assessment of Halitosis and Submandibular Abscesses Using HS-SPME-GC/MS Technique

Abstract

Halitosis and submandibular abscesses are examples of mouth-related diseases with the possible bacterial origin. Salivary volatile organic compounds (VOCs) are potential biomarkers of them, once they can be addressed as metabolites of bacterial activity. Healthy patients (n = 15), subjects with submandibular abscesses located in fascial deep space (n = 10), and subjects with halitosis (n = 5) were enrolled in the study. Saliva samples were subjected to headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled to mass spectrometry (GC/MS) analysis. A total number of 164 VOCs was detected by the developed methodology, 23 specific for halitosis and 41 for abscess. Halitosis’ profiles were characterized by a larger number of sulfur compounds, while for abscess they had a higher variety of alcohols, aldehydes, and hydrocarbons—biomarkers of inflammatory processes. Principal components analysis allowed visualization of clusters formed according to the evaluated conditions. Kruskal-Wallis test indicated that 39 VOCs presented differentiated responses between the studied groups, with statistical relevance (p < 0.05). Random forest was applied, and a prediction model based on eight VOCs (2-butanone, methyl thioacetate, 2-methylbutanoic acid, S-methyl pentanethioate, dimethyl tetrasulfide, indolizine, pentadecane, and octadecanal) provided 100% of sensitivity, 82% of specificity, and 91% of balanced accuracy, indicating the specific presence of submandibular abscess.

The Role of Oral Microbiota in Intra-Oral Halitosis

“…However, they can have an equally important role. It is confirmed by studies using gas chromatography-mass spectrometry [29,32,44]. In the paper of Monedeiro et al, in the persons with IOH, 85 volatiles, were detected, and the most predominant classes of malodor compounds were alcohols and ketones.…”

“…In this group, in comparison to healthy persons, an increased number of volatile sulfur compounds and esters was observed. Simultaneously, authors found ten VSCs substances: methyl thioacetate, dimethyl disulfide, dimethyl trisulfide, dimethyl tetrasulfide, dimethyl pentasulfide, dimethyl sulfone, allyl thiocyanate, allyl isothiocyanate, S-methyl pentanethioate, and thiolan-2-one [44]. In other studies, in halitosis patients, the 30 most abundant volatile compounds in the oral cavity belonged to alkanes or alkane derivatives, therein methyl benzene, tetramethyl butane, and ethanol [45].…”

A Review of GC-Based Analysis of Non-Invasive Biomarkers of Colorectal Cancer and Related Pathways

“…CE-MS offers high-analyte resolution and a small volume of sample for injection (1–20 nL) [ 52 , 53 ]. GC-MS is a gold standard for the analysis of volatiles and it is, relatively, a simpler technique than LC-MS, more cost effective and with reduced matrix effect enabling to quantify compounds in picograms and identification using easy-accessible reference libraries [ 27 , 28 , 29 ]. It is also possible to separate and analyze semi-volatiles, for example when using solvent extraction as the sample preparation technique.…”

“…Among the small metabolites, volatile organic compounds (VOCs) are metabolic products that can elicit diversified patterns that may represent very specific biochemical ongoing processes in the organism. Volatiles’ profiles have been studied in the context of several diseases, especially in exhaled breath, using GC-based analyses [ 25 , 26 , 27 , 28 ]. In this context, GC analysis is extremely relevant, because it encompasses the group of VOC metabolites, which cannot be properly assessed by LC.…”

Rapid and accurate determination of trace volatile sulfur compounds in human halitosis by an adaptable active sampling system coupling with gas chromatography

“…Halitosis, also known as oral malodor, usually refers to the unpleasant gas that occurs in the oral cavity, nasal cavity, sinuses, or pharynx during breathing . It is caused by various volatile molecules including volatile sulfur compounds (VSCs), aromatic compounds, amines, and so on .…”