title: Hydrogen sulphide in exhaled breath: a potential biomarker for small intestinal bacterial overgrowth in IBS.
abstract: There is a pressing need to develop a novel early-detection strategy for the precise evolution of small intestinal bacterial overgrowth (SIBO) in irritable bowel syndrome (IBS) patients. The current method based on a hydrogen breath test (HBT) for the detection of SIBO is highly controversial. HBT has many limitations and drawbacks. It often fails to indentify SIBO when IBS individuals have 'non-hydrogen-producing' colonic bacteria. Here, we show that hydrogen sulphide (H2S) in exhaled breath is distinctly altered for diarrhea-predominant IBS individuals with positive and negative SIBO by the activity of intestinal sulphate-reducing bacteria. Subsequently, by analyzing the excretion kinetics of breath H2S, we found a missing link between breath H2S and SIBO when HBT often fails to diagnose SIBO. Moreover, breath H2S can track the precise evolution of SIBO, even after the eradication of bacterial overgrowth. Our findings suggest that the changes in H2S in the bacterial environment may contribute to the pathogenesis of SIBO and the breath H2S as a potential biomarker for non-invasive, rapid and precise assessment of SIBO without the endoscopy-based microbial culture of jejunal aspirates, and thus may open new perspectives into the pathophysiology of SIBO in IBS subjects.
authors.affiliation: Department of Chemical, Biological and Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Salt Lake, JD Block, Sector III, Kolkata 700098, India.
authors.forename: Gourab Dutta
authors.initials: GD
authors.lastname: Banik
authors.forename: Anulekha
authors.initials: A
authors.lastname: De
authors.forename: Suman
authors.initials: S
authors.lastname: Som
authors.forename: Subhra
authors.initials: S
authors.lastname: Jana
authors.forename: Sunil B
authors.initials: SB
authors.lastname: Daschakraborty
authors.forename: Sujit
authors.initials: S
authors.lastname: Chaudhuri
authors.forename: Manik
authors.initials: M
authors.lastname: Pradhan
mesh_terms: D000328:Adult; D001424:Bacterial Infections / Q000175:diagnosis* / Q000382:microbiology; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests / Q000379:methods*; D045853:Exhalation; D005260:Female; D006801:Humans; D006862:Hydrogen Sulfide / Q000032:analysis*; D007421:Intestine, Small / Q000382:microbiology*; D043183:Irritable Bowel Syndrome / Q000175:diagnosis* / Q000382:microbiology; D008297:Male; D008875:Middle Aged
chemical_list: D015415:Biomarkers; D006862:Hydrogen Sulfide