Volatile sulphur compounds in morning breath of human volunteers

Volatile composition of the morning breath

We have measured the composition of volatile organic compounds (VOCs) in the morning breath of 30 healthy individuals before and after tooth brushing. The concentrations of VOCs in the breath samples were measured with proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) and further identification was performed with a combination of solid phase microextraction (SPME) and offline gas chromatography-mass spectrometry (GC-MS). We hypothesize that compounds, whose concentrations significantly decreased in the breath after tooth brushing are largely of microbial origin. In this study, we found 35 such VOCs. Out of these, 33 have been previously connected to different oral niches, such as salivary and subgingival bacteria. We also compared the concentrations of the 35 VOCs found in increased amounts in the morning breath to their respective odor thresholds to evaluate their ability to cause odor. Compounds that could contribute to the breath odor include many volatile sulfur compounds, such as methanethiol, hydrogen sulfide, dimethyl sulfide, and 2-methyl-1-propanethiol, but also other VOCs, such as acetic acid, butyric acid, valeric acid, acetaldehyde, octanal, phenol, indole, ammonia, isoprene, and methyl methacrylate.

A Whiff of Sulfur: One Wind a Day Keeps the Doctor Away

Reactive Sulfur Species (RSS), such as allicin from garlic or sulforaphane from broccoli, are fre-quently associated with biological activities and possible health benefits in animals and humans. Among these Organic Sulfur Compounds (OSCs) found in many plants and fungi, the Volatile Sulfur Compounds (VSCs) feature prominently, not only because of their often-pungent smell, but also because they are able to access places which solids and solutions cannot reach that easily. Indeed, inorganic RSS such as hydrogen sulfide (H₂S) and sulfur dioxide (SO₂) can be used to lit-erally fumigate entire rooms and areas. Similarly, metabolites of garlic, such as allyl methyl sulfide (AMS), are formed metabolically in humans in lower concentrations and reach the airways from inside the body as part of one’s breath. Curiously, H₂S is also formed in the gastrointestinal tract by gut bacteria, and the question of if and for which purpose this gas then crosses the barriers and enters the body is indeed a delicate matter for equally delicate studies. In any case, nature is surprisingly rich in such VSCs, as fruits (for instance, the infamous durian) demonstrate, and therefore these VSCs represent a promising group of compounds for further studies.

Volatile compounds in human breath: critical review and meta-analysis

Volatile compounds contained in human breath reflect the inner workings of the body. A large number of studies have been published that link individual components of breath to disease, but diagnostic applications remain limited, in part due to inconsistent and conflicting identification of breath biomarkers. New approaches are therefore required to identify effective biomarker targets. Here, volatile organic compounds have been identified in the literature from four metabolically and physiologically distinct diseases and grouped into chemical functional groups (e.g. - methylated hydrocarbons or aldehydes; based on known metabolic and enzymatic pathways) to support biomarker discovery and provide new insight on existing data. Using this functional grouping approach, principal component analysis doubled explanatory capacity from 19.1% to 38% relative to single individual compound approaches. Random forest and linear discriminant analysis reveal 93% classification accuracy for cancer. This review and meta-analysis provides insight for future research design by identifying volatile functional groups associated with disease. By incorporating our understanding of the complexities of the human body, along with accounting for variability in methodological and analytical approaches, this work demonstrates that a suite of targeted, functional volatile biomarkers, rather than individual biomarker compounds, will improve accuracy and success in diagnostic research and application.

[Correction of halitosis in chronic inflammatory diseases of the oropharynx in adults]

Approximately 25% of the world population suffer from halitosis, making it a significant medico-social issue. It is one of the clinical signs of chronic inflammatory diseases of the oropharynx and is commonly caused by the persistence some bacteria in the oral cavity and in the oropharynx. These in turn facilitate formation of volatile sulphur compounds.

OBJECTIVE

To evaluate the effectiveness and safety of the probiotic strain Streptococcus salivarius K12 in the Bactoblis product in exacerbation of chronic inflammatory diseases of the oropharynx.

MATERIAL AND METHODS

45 patients diagnosed with a diagnosis of exacerbation of chronic pharyngitis were studied, gastroesophageal reflux disease was found in 33 patients. After a microbiological testing, all patients were prescribed probiotic strain Streptococcus salivarius K12 in the amount of 1×10⁹ colony-forming units (CFU) in the form of tablets for resorption as monotherapy for 14 days. The assessment of the therapy was based on physical examination data and on the subjective estimation of the clinical symptoms using a 10-point visual analog scale (VAS) before the start of the treatment and on the 5th and on the 7th day of the therapy.

RESULTS

According to the microbiological analysis was revealed the growth of Staphylococcus aureus, Candida albicans, Pseudomonas aeruginosa, Streptococcus agalactiae, Streptococcus viridans which was seen within 10³-10⁵ CFU. A significant clinical progress was achieved for all three analyzed signs of diseases (the severity of pain when swallowing, a feeling of perspiration (foreign body) in the pharynx, halitosis), within the statistical significance between the 1st and the 7th day and the 7th and the 14th day of the surveillance. The pain severity was decreased from 5.69±0.39 points to 2.69±0.34 points on the 7th day and to 0.08±0.05 point on the 14th day from the start of the therapy, itchy throat (foreign body sensation) was relived from 6.88±0.23 points to 3.54±0.29 points on the 7th day and to 0.69±0.12 point on the 14th day of the therapy. In addition, there was a decline in the severity of halitosis from 6.16±0.31 points to 2.47±0.44 points on the 7th day and to 0.68±0.29 point on the 14th day of the therapy.

CONCLUSION

Topical application of a drug containing a probiotic Streptococcus salivarius K12, in case of chronic inflammatory diseases of the oropharynx of various etiologies, showed satisfactory effectiveness in the regression of the main symptoms of the exacerbation of the inflammatory process, expressed through pain in the throat when swallowing, halitosis and the foreign body sensation in the oropharynx.

Interdental and subgingival microbiota may affect the tongue microbial ecology and oral malodour in health, gingivitis and periodontitis

BACKGROUND AND OBJECTIVE

Oral malodour is often observed in gingivitis and chronic periodontitis patients, and the tongue microbiota is thought to play a major role in malodorous gas production, including volatile sulphur compounds (VSCs) such as hydrogen sulphide (H₂ S) and methanethiol (CH₃ SH). This study aimed to examine the link between the presence of VSCs in mouth air (as a marker of oral malodour) and the oral bacterial ecology in the tongue and periodontal niches of healthy, gingivitis and periodontitis patients.

METHODS

Participants were clinically assessed using plaque index, bleeding on probing (BOP) and periodontal probing depths, and VSC concentrations in their oral cavity measured using a portable gas chromatograph. Tongue scrapings, subgingival and interdental plaque were collected from healthy individuals (n = 22), and those with gingivitis (n = 14) or chronic periodontitis (n = 15). The bacterial 16S rRNA gene region V3-V4 in these samples was sequenced, and the sequences were analysed using the minimum entropy decomposition pipeline.

RESULTS

Elevated VSC concentrations and CH₃ SH:H₂ S were observed in periodontitis compared with health. Significant ecological differences were observed in the tongue microbiota of healthy subjects with high plaque scores compared to low plaque scores, suggesting a possible connection between the microbiota of the tongue and the periodontium and that key dysbiotic changes may be initiated in the clinically healthy individuals who have higher dental plaque accumulation. Greater subgingival bacterial diversity was positively associated with H₂ S in mouth air. Periodontopathic bacteria known to be prolific VSC producers increased in abundance on the tongue associated with increased bleeding on probing (BOP) and total percentage of periodontal pockets >6 mm, supporting the suggestion that the tongue may become a reservoir for periodontopathogens.

CONCLUSION

This study highlights the importance of the periodontal microbiota in malodour and has detected dysbiotic changes in the tongue microbiota in periodontitis.

Targeted Chemometrics Investigations of Source-, Age- and Gender-Dependencies of Oral Cavity Malodorous Volatile Sulphur Compounds

Halitosis is a highly distressing, socially unaesthetic condition, with a very high incidence amongst the adult population. It predominantly arises from excessive oral cavity volatile sulphur compound (VSC) concentrations, which have either oral or extra-oral etiologies (90–95% and 5–10% of cases, respectively). However, reports concerning age- and gender-related influences on the patterns and concentrations of these malodorous agents remain sparse; therefore, this study’s first objective was to explore the significance and impact of these potential predictor variables on the oral cavity levels of these malodorants. Moreover, because non-oral etiologies for halitosis may represent avatars of serious extra-oral diseases, the second objective was to distinguish between etiology- (source-) dependent patterns of oral cavity VSCs. Oral cavity VSC determinations were performed on 116 healthy human participants using a non-stationary gas chromatographic facility, and following a 4 h period of abstention from all non-respiratory oral activities. Participants were grouped according to ages or age bands, and gender. Statistical analyses of VSC level data acquired featured both univariate/correlation and multivariate (MV) approaches. Factorial analysis-of-variance and MV analyses revealed that the levels of all VSCs monitored were independent of both age and gender. Principal component analysis (PCA) and a range of further MV analysis techniques, together with an agglomerative hierarchal clustering strategy, demonstrated that VSC predictor variables were partitioned into two components, the first arising from orally-sourced H2S and CH3SH, the second from extra-orally-sourced (CH3)2S alone (about 55% and 30% of total variance respectively). In conclusion, oral cavity VSC concentrations appear not to be significantly influenced by age and gender. Furthermore, (CH3)2S may serve as a valuable biomarker for selected extra-oral conditions.

The Relationship between Volatile Sulfur Compounds and the Severity of Chronic Periodontitis: A Cross-sectional Study

Background:

Halitosis is a problem that is often ignored or undervalued. It is not considered a major clinical issue; thus, little is carried out to eradicate it. Little is known about the relationship of malodorous breath with the severity of periodontitis. Hence, the study aimed to investigate the relationship between volatile sulfur compounds (VSCs) and chronic periodontitis.

Materials and Methods:

According to the severity of chronic periodontitis, 80 patients were categorized into four groups (mild, moderate, severe, and control). Probing depth and clinical attachment level were measured. Portable sulfide monitor (Halimeter) is used to assess VSCs. Statistical analyses were conducted using R studio (Northern Ave, Boston).

Results:

The differences in the VSC levels among the four groups were found to be statistically significant. The greater the severity of periodontitis, the higher the VSC levels found (P < 0.001). Male had higher levels of VSCs than female (225 and 180.53 parts per billion [ppb], respectively). The lowest mean level of VSCs was found in the subjects aged 15–29 years (161.79 ppb); the mean values increased with the age, reaching 282.89 ppb in subjects aged >59 years.

Conclusion:

Highly significant differences were found in the VSC levels among different severities of chronic periodontitis. Moreover, an age-related increase in the VSC levels was determined. In addition, male had higher concentration of VSCs than female.

Impact of oral cleansing strategies on exhaled volatile organic compound levels

RATIONALE

The analysis of volatile organic compounds (VOCs) within exhaled breath potentially offers a non-invasive method for the detection and surveillance of human disease. Oral contamination of exhaled breath may influence the detection of systemic VOCs relevant to human disease. This study aims to assess the impact of oral cleansing strategies on exhaled VOC levels in order to standardise practice for breath sampling.

METHODS

Ten healthy volunteers consumed a nutrient challenge followed by four oral cleansing methods: (a) water, (b) saltwater, (c) toothbrushing, and (d) alcohol-free mouthwash. Direct breath sampling was performed using selected ion flow tube mass spectrometry after each intervention.

RESULTS

Proposed reactions suggest that volatile fatty acid and alcohol levels (butanoic, pentanoic acid, ethanol) declined with oral cleansing interventions, predominantly after an initial oral rinse with water. Concentrations of aldehydes and phenols (acetaldehyde, menthone, p-cresol) declined with oral water rinse; however, they increased after toothbrushing and mouthwash use, secondary to flavoured ingredients within these products. No significant reductions were observed with sulphur compounds.

CONCLUSIONS

Findings suggest that oral rinsing with water prior to breath sampling may reduce oral contamination of VOC levels, and further interventions for oral decontamination with flavoured products may compromise results. This intervention may serve as a simple and inexpensive method of standardisation within breath research.

The prevalence of halitosis (oral malodor) and associated factors among dental students and interns, Lahore, Pakistan

Objective

To evaluate the prevalence of halitosis and the factors associated with it among dental students and interns in Lahore, Pakistan.

Methods

A cross-sectional study design was chosen, and a sample of dental students and interns was collected from seven dental colleges in Lahore, Pakistan. A total of 833 participants were approached in person as convenient sample population. A self-reported questionnaire was administered and informed consent was obtained. The associations between oral malodor and different variables of the study were explored using analytical statistics (Chi-square test and logistic regression analysis). Statistical significance was determined using a 95% confidence interval (CI).

Results

Six hundred and fifteen participants (aged 19-27 years) completed the survey with a response rate of 73.8%. The prevalence of self-reported halitosis was 75.1%. More female (51.4%) than male students (23.7%) reported oral malodor, and most participants (61%) reported early morning halitosis. Thirteen percent of respondents had examination for oral malodor by a dentist and 37.6% treated the condition with self-medication. Binary logistic regression model showed that male gender (odds ratio [OR] =0.44, CI = 0.22-0.87), daily use of dental floss (OR = 0.28, CI = 0.13-0.58), and drinking tea with mint (OR = 0.44, CI = 0.22-0.89) were significantly associated with oral malodor. The participants with tongue coating had higher odds (OR = 2.75, CI = 1.13-6.69) of having oral malodor than those without tongue coating, and the association was statistically significant.

Conclusions

The study identified high prevalence of oral malodor among dental students and interns. They should receive appropriate diagnosis and management of the condition from dentist. The regular use of dental floss and removal of tongue coating can significantly reduce halitosis.

Volatile sulphur compound measurement with OralChroma(TM): a methodological improvement

The instrumental measurement of volatile sulphur compounds is a common practice to assess halitosis. One of the most widespread devices for that purpose is OralChroma(TM), a combination of a semiconductor gas sensor and a compact gas chromatograph (GC) system. Several lines of evidence indicate that although the hardware of OralChroma(TM) is fit for the precise measurement of volatile sulphur compounds (VSCs), its software needs revision to allow that precision. In this study we sought to develop software to solve this problem, and to test the utility of the new software in a population of patients and controls. The results were also compared with VSC measurements performed with Halimeter(®), another widespread device, so as to assess the correlation. A set of measurements involving volunteers (21 controls and 14 oral cancer patients) were conducted. The analysis of the chromatograms recorded by OralChroma(TM) indicated that the majority of the studied breath samples contained significant amounts of isoprene (the peak was around 100 s) and acetaldehyde (the peak was around 350 s), therefore OralChroma(TM) was also calibrated for both isoprene and acetaldehyde. A linear relationship was found between the concentration (in the range of 80-1400 ppbv for acetaldehyde and 40-560 ppbv for isoprene) and the area under the corresponding peak. In numerous cases the concentrations of VSCs calculated by the software of OralChroma(TM) required revision. In the new software, the concentrations of the VSCs, isoprene and acetaldehyde were determined by fitting the chromatograms with the sum of six Gaussian functions. Based on the findings of the present study we conclude that our new software allows an improved and instantaneous evaluation of OralChroma(TM) chromatograms with the additional possibility of determining the isoprene and acetaldehyde concentrations from breath samples.

Association between halitosis diagnosed by a questionnaire and halimeter and symptoms of gastroesophageal reflux disease

Background/Aims

The relationship between halitosis and gastroesophageal reflux disease (GERD) remains controversial. The aim of this study was to investigate an association between subjective and objective halitosis and GERD.

Methods

The subjects were enrolled from participants who visited a health promotion center at Seoul National University Bundang Hospital. For diagnosis of halitosis, a questionnaire was requested, and volatile sulfur compounds (VSCs) were measured by Halimeter. Self-conscious halitosis was defined as halitosis perceived by himself or herself. Informed halitosis was defined as halitosis perceived by others. Objective halitosis was defined when mean VSCs values were > 100 parts per billion. GERD was defined based on a questionnaire and endoscopy, including erosive esophagitis and non-erosive reflux disease (NERD).

Results

A total of 54 subjects (male:female = 33:21) with mean age of 46.0 ± 11.4 years were analyzed. The mean VSCs values were not significantly different between presence and absence of self-conscious halitosis (P = 0.322), but significantly different between presence and absence of informed halitosis (P = 0.021). Informed halitosis was associated with objective halitosis (P = 0.039). GERD, erosive esophagitis and NERD did not correlate with objective halitosis (P = 0.556, 0.206 and 0.902, respectively). In multivariable analysis, the relationship between objective halitosis and GERD symptoms including chest pain, heart burn, acid regurgitation, epigastric pain, hoarseness, globus sensation and coughing was not significant. Besides, GERD was not associated with self-conscious halitosis, informed halitosis and objective halitosis, respectively.

Conclusions

GERD might not be associated with self-conscious, informed halitosis and objective halitosis indicated by Halimeter results. Informed halitosis could be correlated with objective halitosis determined by the Halimeter.

The effect of a commercial probiotic drink containing Lactobacillus casei strain Shirota on oral health in healthy dentate people

BACKGROUND

In the past decade, the use of probiotic-containing products has been explored as a potential alternative in oral health therapy. A widely available probiotic drink, Yakult, was evaluated for oral health applications in this longitudinal study. Selected oral health parameters, such as levels and composition of salivary and tongue plaque microbiota and of malodorous gases, in dentate healthy individuals were investigated for changes. The persistence of the probiotic strain in the oral cavity was monitored throughout the study period.

METHODS

A three-phase study (7 weeks) was designed to investigate simultaneously the effect of 4-week consumption of the probiotic-containing milk drink Yakult on the microbiota of saliva and dorsum tongue coating in healthy dentate people (n = 22) and levels of volatile sulphur compounds (VSCs) in morning breath. Study phases comprised one baseline visit, at which 'control' levels of oral parameters were obtained prior to the probiotic product consumption; a 4-week period of daily consumption of one 65 ml bottle of Yakult, each bottle containing a minimum of 6.5×10(9) viable cells of Lactobacillus casei strain Shirota (LcS); and a 2-week washout period. The microbial viability and composition of saliva and tongue dorsum coating were assessed using a range of solid media. The presence of LcS in the oral cavity was investigated using a novel selective medium, 'LcS Select'. Portable sulphur monitors Halimeter(®) and OralChroma(TM) were used to measure levels of VSCs in morning breath.

RESULTS

Utilization of the LcS Select medium revealed a significant (p < 0.05) but temporary and consumption-dependent presence of LcS in saliva and tongue plaque samples from healthy dentate individuals (n = 19) during the probiotic intervention phase. LcS was undetectable with culture after 2 weeks of ceasing its consumption. Morning breath scores measured with Halimeter and OralChroma were not significantly affected throughout the trial, except in a small number of individual cases where Halimeter scores were significantly reduced during the probiotic intervention period. Natural fluctuations in resident acidogenic populations, and numbers of Candida and anaerobic species, including malodourous Gram-negative anaerobes, were unaffected.

CONCLUSION

While no broad ecological changes in the mouth were induced by consumption of Yakult in healthy dentate individuals, findings of this study confirm the temporary and intake-dependent presence of LcS. Future studies could focus on subjects at greater risk of oral infection, where ill-defined microbiota (e.g. an increased presence of periopathogens) or clinically diagnosed halitosis might be significantly affected by consumption of this probiotic.

Halitosis: the multidisciplinary approach

Halitosis, bad breath or oral malodour are all synonyms for the same pathology. Halitosis has a large social and economic impact. For the majority of patients suffering from bad breath, it causes embarrassment and affects their social communication and life. Moreover,halitosis can be indicative of underlying diseases. Only a limited number of scientific publications were presented in this field until 1995. Ever since, a large amount of research is published, often with lack of evidence. In general, intraoral conditions, like insufficient dental hygiene, periodontitis or tongue coating are considered to be the most important cause (85%) for halitosis. Therefore, dentists and periodontologists are the first-line professionals to be confronted with this problem. They should be well aware of the origin, the detection and especially of the treatment of this pathology. In addition, ear-nose-throat-associated (10%) or gastrointestinal/endocrinological (5%) disorders may contribute to the problem. In the case of halitophobia, psychiatrical or psychological problems may be present. Bad breath needs a multidisciplinary team approach: dentists, periodontologists, specialists in family medicine, ear-nose-throat surgeons, internal medicine and psychiatry need to be updated in this field, which still is surrounded by a large taboo.Multidisciplinary bad breath clinics offer the best environment to examine and treat this pathology that affects around 25% of the whole population. This article describes the origin, detection and treatment of halitosis, regarded from the different etiological origins.

Daily variation of oral malodour and related factors in community-dwelling elderly Thai

OBJECTIVES

The purposes of this study were (i) to estimate the prevalence of oral malodour, (ii) to evaluate the daily variation of oral malodour and (iii) to assess associations of volatile sulphur compound (VSC) concentrations with socio-demographics, health behaviours and oral health status in community-dwelling elderly Thai.

METHODS

The subjects were 428 dentate elderly people (67.6 ± 5.6 years) living in Phitsaulok, Thailand. Information on their socio-demographics, general health and health behaviours was obtained by a questionnaire. Their dental condition, periodontal status and tongue coating were clinically examined. Their flow rates and the pH of unstimulated saliva were also assessed. Oral malodour was measured at four different times of day using an Oral Chroma™.

RESULTS

The proportions of subjects diagnosed with oral malodour using the thresholds of H(2)S, CH(3)SH and (CH(3))(2) S were 60.5%, 62.9% and 80.7%, respectively. Concentrations of H(2)S showed significant daily variation. Linear regression analysis demonstrated the following significant associations: (i) oral malodour from H(2)S and thickness of the tongue coating, (ii) oral malodour from CH(3)SH and periodontal pocket depth of 5 mm or more and the presence of gingival bleeding and (iii) oral malodour from (CH(3))(2)S and systemic disease, medications and thickness of the tongue coating.

DISCUSSION

Oral malodour was shown to be prevalent among the elderly. Daily variation was observed in the concentration of H(2)S. Tongue coating, periodontal disease, systemic diseases and medications were related to oral malodour. Therefore, these factors should be taken into consideration in oral malodour treatment and prevention programmes for the elderly.

Hydrogen sulfide and asthma

Asthma is a chronic inflammatory disease, with hyper-responsive bronchoconstriction and airway remodelling, leading to extensive airway narrowing. The regulation of airway responsiveness and inflammation by endogenous hydrogen sulfide (H(2)S) during the pathogenic development of asthma has been suggested. Hydrogen sulfide can be produced in the lung and airway tissues via the actions of two H(2)S-generating enzymes, cystathionine β-synthase (CBS) and/or cystathionine γ-lyase (CSE). The abnormal metabolism and function of H(2)S have been reported in experimental animals with asthma, especially ovalbumin-induced rat or mouse models. In patients with asthma, serum H(2)S levels are significantly reduced. Supplementation with exogenous H(2)S has been shown to mitigate the severity of asthma in experimental animals. It is hypothesized that decreased H(2)S production in the lung and airway tissues may be used as an early detection biomarker, and H(2)S-based therapy would represent a new treatment strategy for asthma. Major challenges for establishing the diagnostic and treatment values of H(2)S include the differential expression of CSE and CBS along the airway and their changes during asthma, the effects of H(2)S on bronchoconstriction and airway remodelling, as well as the underlying mechanisms, and the detection of the changes in H(2)S levels in airway tissues and in exhaled air.