[Predominance of constipation in subjects with hydrogen-consuming intestinal flora]

Acta Gastroenterol Latinoam. 2012 Sep;42(3):182-5.
[Article in Spanish]


Introduction: There is growing evidence that a disorder in intestinal microbiota would contribute to the development of symptoms in irritable bowel syndrome (IBS) patients. In a subgroup, a remarkably low hydrogen production in lactulose breath test (LBT) is observed. We presume in these patients a predominance of hydrogen consuming gut flora.

Objective: [corrected] Describe the clinical presentation of lBS patients with low hydrogen production and to compare their cathartic pattern against those with high hydrogen excretion.

Materials and methods: A case-control study was designed. IBS outpatients were included. A validated questionnaire was delivered (IBSSS) in order to assess their symptoms and a LBT was performed. The cathartic pattern was compared between those with low and high hydrogen production on LBT.

Results: One hundred and ten patients were included and 15 of them (13.6%) had low hydrogen production on LBT, which would be compatible with the presence of hydrogen-consuming gut flora. In this group, 11 patients (73.33%) were constipated In contrast, only 30 patients (31.58%) in the high or normal hydrogen production group were constipated [OR 5.95 (95% confidence interval 1.75-20.25; P = 0.03)].

Conclusion: IBS patients with low hydrogen production on lactulose breath test were 6 times more frequently constipated.

Publication types

  • Comparative Study
  • English Abstract

MeSH terms

  • Adult
  • Aged
  • Bacteria / metabolism*
  • Breath Tests
  • Case-Control Studies
  • Constipation / microbiology*
  • Female
  • Humans
  • Hydrogen / metabolism*
  • Irritable Bowel Syndrome / metabolism
  • Irritable Bowel Syndrome / microbiology*
  • Lactulose
  • Male
  • Middle Aged
  • Young Adult


  • Lactulose
  • Hydrogen