Related Experiment Video
Updated: May 4, 2026

An In Vitro Batch-culture Model to Estimate the Effects of Interventional Regimens on Human Fecal Microbiota
Published on: July 31, 2019
The inulin hydrogen breath test predicts the quality of colonic preparation
Donato F Altomare1, Leonilde Bonfrate, Marcin Krawczyk
1Department of Emergency and Organ Transplantation, University Aldo Moro of Bari, Bari, Italy, donatofrancesco.altomare@uniba.it.
Background:
Successful bowel preparation is essential to an adequate performance of colonoscopy. Polyethylene glycol (PEG) with electrolyte solutions induces diarrhea with depletion of substrates fermentable by hydrogen (H2)-producing colonic microbiota. Inulin has recently been suggested as a prebiotic substrate for the H2 breath test because it is resistant to intestinal hydrolysis and is fermented mostly by the colonic bacteria. This study aimed to assess time-dependent changes in H2 breath levels in order to predict the colonic preparation of patients scheduled for colonoscopy with or without oral supplementation of inulin.
Methods:
In this prospective nonrandomized trial, 127 subjects drank 4 l of PEG 280-mg solution as bowel preparation for colonoscopy. A subgroup of 31 patients also ingested inulin (10 g in 200 ml of water) at breakfast as an additional substrate to increase colonic H2 production. Measurements of H2 breath levels were performed immediately before and after colonic preparation. As the main outcome measure, the quality of the colonic preparation was scored as excellent to fair (i.e., clean bowel allowing successful pan-colonoscopy, including the terminal ileum) or poor (incomplete colonoscopy due to fecal debris).
Results:
The H2 breath levels decreased from 11.0 ± 1.8 ppm before PEG to 1.8 ± 0.3 ppm after PEG (n = 18; P < 0.001). The H2 concentrations after PEG ingestion were significantly lower (P < 0.001) in the patients with excellent-to-fair preparation than in the 19 patients with poor preparation. Ingestion of inulin induced an overall increase in H2 breath levels and improved discrimination between the patients with excellent-to-fair colonic preparation and those with poor preparation, leading to the sensitivity and specificity of such a test reaching 100 %.
Conclusions:
The H2 breath test with inulin ingestion can be a simple, noninvasive, reliable method for predicting successful colonic preparation that leads to cost savings and less patient discomfort/stress or need to repeat colonoscopy.
More Related Videos
Related Concept Videos
Serum Laboratory Studies, Stool Test, Breath Test
Imaging Studies III: Gastrointestinal Motility Studies and Virtual Colonoscopy
Radionuclide Testing
Radionuclide testing is a sophisticated medical technique for assessing gastrointestinal motility. It focuses on gastric emptying and colonic transit time. Radioactive markers track the movement of food through the digestive system, providing insights into gastrointestinal disorders.
In gastric emptying studies, a meal's liquid and...
Lower GI Series: Barium Enema
Procedure Details
The examination begins by inserting a lubricated rectal tube into the patient's rectum to administer a radiopaque barium solution. The barium flow is carefully...
Inflammatory Bowel Disease III: Diagnostic Studies and Management I-Nutritional Therapy
Diagnostic studies
A colonoscopy is the definitive screening test, distinguishing ulcerative colitis from other colon diseases with similar symptoms. During a colonoscopy test, inflamed mucosa with exudate ulcerations can be observed, and biopsies are taken to determine the histologic characteristics of the...
Methods for Studying Drug Absorption: In situ
The Doluisio method involves perfusing a prepared segment of a rat's small intestine with a solution of radiolabeled drug and a non-absorbable marker. This helps to differentiate between absorbed and non-absorbed drug concentrations. The intestinal segment is connected at both ends using tubing and syringes,...

