Authors: King TS, Elia M, Hunter JO.

Institution: Department of Gastroenterology, Addenbrooke's Hospital, Cambridge, UK.

Background: The cause of irritable bowel syndrome (IBS) is unknown. It may follow gastroenteritis and be associated with an abnormal gut flora and with food intolerance. Our study was designed to assess whether these factors were associated with colonic malfermentation.

Methods: We carried out a crossover controlled trial of a standard diet and an exclusion diet matched for macronutrients in six female IBS patients and six female controls. During the final 72 h on each diet, faecal excretion of fat, nitrogen, starch, and non-starch polysaccharide NSP was measured, and total excretion of hydrogen and methane collected over 24 h in a purpose-built 1.4 m3 whole-body calorimeter. Breath hydrogen and methane excretion were then measured for 3 h after 20 g oral lactulose.

Interpretation: Colonic-gas production, particularly of hydrogen, is greater in patients with IBS than in controls, and both symptoms and gas production are reduced by an exclusion diet. This reduction may be associated with alterations in the activity of hydrogen-consuming bacteria. Fermentation may be an important factor in the pathogenesis of IBS.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9777836&dopt=Abstract

• Analysis of the Fecal Microbiota of Irritable Bowel Syndrome Patients and Healthy Controls with Real-Time PCR
• A Review of the Role of the Gut Microflora in Irritable Bowel Syndrome and the Effects of Probiotics
• Alteration of Intestinal Microflora is Associated with Reduction in Abdominal Bloating and Pain in Patients with Irritable Bowel Syndrome
• Do Interventions which Reduce Colonic Bacterial Fermentation Improve Symptoms of Irritable Bowel Syndrome?