Prevalence of small intestinal bacterial overgrowth in irritable bowel syndrome (IBS): Correlating H2 or CH4 production with severity of IBS

Philippe Onana Ndong; Hanae Boutallaka; Eugenia Marine-Barjoan; Dann Ouizeman; Raja Mroue; Rodolphe Anty; Geoffroy Vanbiervliet; Thierry Piche

doi:10.1002/jgh3.12899

Prevalence of small intestinal bacterial overgrowth in irritable bowel syndrome (IBS): Correlating H₂ or CH₄ production with severity of IBS

JGH Open. 2023 Apr 3;7(4):311-320. doi: 10.1002/jgh3.12899. eCollection 2023 Apr.

Authors

Philippe Onana Ndong¹, Hanae Boutallaka¹, Eugenia Marine-Barjoan¹, Dann Ouizeman¹, Raja Mroue¹, Rodolphe Anty¹, Geoffroy Vanbiervliet¹, Thierry Piche¹

Affiliation

¹ Gastro-entérologie, Hôpital L'Archet 2 Centre Hospitalier Universitaire de Nice Nice France.

Abstract

Background and aim: The prevalence and the role of small intestinal bacterial overgrowth (SIBO) in irritable bowel syndrome (IBS) remain unclear, as the literature provides heterogeneous information on the subject. The aim of this study was to determine the prevalence of SIBO in IBS and to assess the correlation between methane and hydrogen levels measured during breath tests and the severity of IBS.

Method: Two-hundred and forty-seven patients with IBS were prospectively included. A glucose breath test (GBT) measured H₂ and CH₄ production to diagnose SIBO. A test was positive when H₂ values exceeded 12 ppm in the first 90 min and/or when a CH₄ value exceeded 10 ppm at any time. IBS severity (IBS-SSS), quality of life (GIQLI), and anxiety and depression (HAD) were assessed to investigate the correlation with H₂ and CH₄ production.

Results: The prevalence of SIBO in IBS was 36.4% (9.7% with H₂, 26.7% with CH₄). CH₄ levels were significantly higher in the predominantly constipated patients (P = 0.00), while H₂ levels were significantly higher within the diarrheal phenotype (P = 0.01). IBS severity was not correlated with either H₂ levels (r = 0.02; P = 0.84) or CH₄ levels (r = 0.05; P = 0.64). H₂ production was inversely correlated with the quality of life (r = -0.24; P = 0.03) and significantly correlated with the HAD scale (r = 0.22; P = 0.03). The pain and discomfort experienced during GBT was not correlated with methane levels (r = -0.09, P = 0.40), hydrogen levels (r = -0.01, P = 0.93), or sum of both (r = 0.06, P = 0.58), but significantly associated with IBS severity (r = 0.50, P <0.00).

Conclusion: SIBO has a high prevalence in IBS but does not increase its severity. Individual susceptibility to pain may have a greater influence on the severity of IBS.

Keywords: gastrointestinal disorders; glucose breath test; hydrogen; irritable bowel syndrome; methane; small intestinal bacterial overgrowth.