GC Analysis of Breath VSCs for Halitosis Study

Researchers at the University of Strasbourg and its affiliated hospital (France) collected breath samples in plastic syringes and measured volatile sulfur compounds (VSCs) in them using gas chromatography (GC), both immediately and again after seven days of storage at room temperature. The team also looked at whether these results were linked to patients' gum health. Their findings were published in the journal Oral Diseases.¹

How Common is Halitosis, and How Is It Currently Diagnosed?

Halitosis is surprisingly common, affecting an estimated 22% to 50% of people worldwide. A large-scale review of existing research puts the global figure at around 32% among teenagers and adults.^2,3

Diagnosing halitosis is more involved than it might seem. It starts with a thorough review of the patient's medical and dental history, any medications they take, smoking and drinking habits, diet, and how they personally perceive their own breath and its effect on their social life. From there, diagnosis typically relies on a straightforward but telling method: the examiner simply smells the patient's exhaled breath and rates the odor on a scale of 0 to 5. A score of 2 or higher is generally considered a sign of clinically significant bad breath.^4,5

Because this smell-based test relies on human judgment, it has its limitations. Factors such as the examiner's experience, their nose becoming desensitized over time, and surrounding odors in the environment can all influence the result. This means two examiners might score the same patient differently, or the same examiner might score them differently on separate occasions, potentially leading to incorrect diagnoses in either direction.⁴

Can Halitosis Be Reliably Diagnosed Remotely Using Delayed Gas Sample Analysis?

One hundred adult patients were enrolled in this study during routine periodontal (gum health) check-ups. Three key compounds responsible for bad breath (hydrogen sulfide, methyl mercaptan, and dimethyl sulfide) were measured using GC, alongside standard gum health measurements.¹

At the initial visit, 64% of patients were identified as having bad breath using a lower detection threshold, while 31% were flagged using a stricter cutoff. When the same patients were retested seven days later, bad breath compound levels had generally increased, except for hydrogen sulfide. Of the three compounds, only dimethyl sulfide showed consistent readings between the two visits.¹

Overall, the agreement between bad breath diagnoses at the first and second visits was poor, suggesting that a single measurement may not reliably reflect a patient's ongoing condition. Additionally, the link between bad breath compound levels and gum health indicators was found to be weak, indicating that gum disease alone may not fully explain bad breath in these patients.¹

“Delayed analysis of oral gas samples,” write the authors of the paper,¹ “significantly altered VSC measurements limiting their reliability for remote halitosis diagnosis. Periodontal parameters were not strongly associated with VSC levels.”

“Overall,” the authors continue, “the proposed method proved insufficient for effective remote diagnosis of halitosis, primarily due to limitations of the materials used for VSC preservation.” The researchers, therefore, believe that future studies should concentrate on optimizing sampling and storage materials which are specifically adapted to maintain VSC stability over time, for determining whether remote halitosis assessment could become practical in the future.¹

Read More on Similar Topics
GC-MS Detection of PCA in Root Canals: Antioxidant Irrigant Study
Evaluating Antimicrobial Potential of Articaine Derivatives in Oral Infections with CMC

References

1. Militsi, E.; Reingewirtz, Y.; Séverac, F. et al. Evaluation of the Volatile Sulfur Compound Stability in Breath Samples for Halitosis Remote Diagnosis. Oral Dis. 2026. DOI: 10.1111/odi.70394
2. Akaji, E. A.; Folaranmi, N.; Ashiwaju, O. Halitosis: A Review of the Literature on its Prevalence, Impact and Control. Oral Health Prev Dent. 2014, 12 (4), 297-304. DOI: 10.3290/j.ohpd.a33135
3. Silva, M. F.; Leite, F. R. M.; Ferreira, L. B. et al. Estimated Prevalence of Halitosis: A Systematic Review and Meta-Regression Analysis. Clin Oral Investig. 2018,22 (1), 47-55. DOI: 10.1007/s00784-017-2164-5
4. Greenman, J.; Lenton, P.; Seemann, R. et al. Organoleptic Assessment of Halitosis for Dental Professionals--General Recommendations. J Breath Res. 2014, 8 (1), 017102. DOI: 10.1088/1752-7155/8/1/017102
5. Zürcher, A.; Laine, M. L.; Filippi, A. 2014. Diagnosis, Prevalence, and Treatment of Halitosis. Curr. Oral Health Rep. 2014, 1 (4), 279–285. DOI: 10.1007/s40496-014-0036-5