Volatile Markers for Cancer in Exhaled Breath-Could They Be the Signature of the Gut Microbiota?

• Published in: Molecules (Basel, Switzerland) Vol. 28; no. 8; p. 3488
• Main Authors: Bhandari, Manohar Prasad, Polaka, Inese, Vangravs, Reinis, Mezmale, Linda, Veliks, Viktors, Kirshners, Arnis, Mochalski, Pawel, Dias-Neto, Emmanuel, Leja, Marcis
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-04-2023; MDPI
• Subjects: Alcohols; Aldehydes; Analysis; Bacteria; Benzamide; Biomarkers; breath analysis; breath biomarker; canonical correlation analysis; Colorectal cancer; Correlation analysis; Datasets; Disease; Esters; Ethers; fecal microbiota; Fecal microflora; Feces; Feces - chemistry; Gas chromatography; Gas Chromatography-Mass Spectrometry; Gastric cancer; Gastrointestinal Microbiome; Humans; Hydrocarbons; Intestinal microflora; Ketones; Life expectancy; Life span; Mass spectrometry; Mass spectroscopy; Medical diagnosis; Metabolism; Metabolites; Metagenomics; Microbiomes; Microbiota; Microbiota (Symbiotic organisms); Microorganisms; Multivariate analysis; Multivariate statistical analysis; Organic compounds; Organosulfur compounds; Patients; Phenols; Principal components analysis; Statistical analysis; Stomach cancer; Stomach Neoplasms - diagnosis; Taxonomy; VOCs; Volatile organic compounds; Volatile Organic Compounds - analysis; United Kingdom; Latvia; VOCs; fecal microbiota; breath analysis; breath biomarker; gastric cancer; volatile organic compounds; canonical correlation analysis
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules28083488

It has been shown that the gut microbiota plays a central role in human health and disease. A wide range of volatile metabolites present in exhaled breath have been linked with gut microbiota and proposed as a non-invasive marker for monitoring pathological conditions. The aim of this study was to examine the possible correlation between volatile organic compounds (VOCs) in exhaled breath and the fecal microbiome by multivariate statistical analysis in gastric cancer patients (
= 16) and healthy controls (
= 33). Shotgun metagenomic sequencing was used to characterize the fecal microbiota. Breath-VOC profiles in the same participants were identified by an untargeted gas chromatography-mass spectrometry (GC-MS) technique. A multivariate statistical approach involving a canonical correlation analysis (CCA) and sparse principal component analysis identified the significant relationship between the breath VOCs and fecal microbiota. This relation was found to differ between gastric cancer patients and healthy controls. In 16 cancer cases, 14 distinct metabolites identified from the breath belonging to hydrocarbons, alcohols, aromatics, ketones, ethers, and organosulfur compounds were highly correlated with 33 fecal bacterial taxa (correlation of 0.891,
-value 0.045), whereas in 33 healthy controls, 7 volatile metabolites belonging to alcohols, aldehydes, esters, phenols, and benzamide derivatives correlated with 17 bacterial taxa (correlation of 0.871,
-value 0.0007). This study suggested that the correlation between fecal microbiota and breath VOCs was effective in identifying exhaled volatile metabolites and the functional effects of microbiome, thus helping to understand cancer-related changes and improving the survival and life expectancy in gastric cancer patients.