Try our beta test site

Validation of Breath Tests in Diagnosing Small Bowel Bacterial Overgrowth (BTO)

This study has been completed.
Information provided by:
University Hospital, Bonn Identifier:
First received: March 30, 2009
Last updated: NA
Last verified: March 2009
History: No changes posted
Normally the gastrointestinal tract is only sparsely colonized with bacteria. The normal flora of the duodenal or jejunal aspirate contains no more than 10^5 bacteria per milliliter. Small bowel bacterial overgrowth (SBBO) is defined as a pathologically increased number of bacteria or the presence of colonic flora in the proximal intestine. The reasons for this condition are manifold, ranging from diabetic neuropathy to surgical bypass. SBBO is frequent in elderly people. Therapy is targeted at correcting the underlying small bowel abnormalities that predispose to the condition and at providing appropriate antibiotic therapy. The symptoms and signs of SBBO can be reversed with this approach. However, in many patients the conditions predisposing to SBBO persist life-long, once present. This suggests that noninvasive, sensitive diagnostic tools with high specificity are required. Bacterial culture of upper intestinal content is considered the diagnostic gold standard. However, since endoscopic harvesting of duodenal or jejunal fluid is difficult and invasive, indirect tests such as breath tests have been advocated as diagnostic tools. Hydrogen breath tests are commonly employed since the substrates can be easily obtained and the measurement is simple. Hydrogen is formed when carbohydrates are fermented in the intestine. Breath hydrogen analysis allows a separation of metabolic activity of the intestinal flora from that of the host, since no known hydrogen production occurs in mammalian tissue. The hydrogen breath test most often used in routine clinical practice uses glucose. However, the utility of this test is mostly limited by its low sensitivity, because there are "nonproducers" in up to 25% of the subjects tested. The investigators have developed a stable isotope breath test using 13C-labeled lactose-ureide. Glycosyl-ureides are condensation products of reducing sugars and urea in aqueous acid. Lactose-[13C]ureide has been used to investigate oro-caecal transit time because it resists digestion by small intestinal enzymes and is hydrolyzed by bacterial enzymes in the large intestine. A number of studies have described the use of this substrate in adults and children. The aim of the present study was to investigate the lactose-[13C]ureide breath test in subjects with suspected SBBO and to compare its results with the results of the glucose hydrogen breath test. Microbiological analyses of upper intestinal bacterial cultures were used as gold standard to identify SBBO.

Condition Intervention
Malabsorption Syndromes
Other: Stable-isotope labeled lactose ureide breath test

Study Type: Observational
Official Title: Validation of Breath Tests in Diagnosing Small Bowel Bacterial Overgrowth

Resource links provided by NLM:

Further study details as provided by University Hospital, Bonn:

Primary Outcome Measures:
  • 13CO2 enrichment in breath CO2 [ Time Frame: 3 hours ]

Secondary Outcome Measures:
  • Hydrogen output in breath [ Time Frame: 3 hours ]

Biospecimen Retention:   Samples Without DNA
Breath samples

Enrollment: 22
Study Start Date: October 1997
Study Completion Date: September 1998
Primary Completion Date: September 1998 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
Breath test
Subjects with suspected SBBO
Other: Stable-isotope labeled lactose ureide breath test
2 g 13C-labeled lactose ureide orally
Other Name: Lactosyl ureide


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Patients with suspected small bowel bacterial overgrowth

Inclusion Criteria:

  • Suspected small bowel bacterial overgrowth

Exclusion Criteria:

  • Age < 18 years
  • Antibiotic therapy
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00872092

University of Bonn
Bonn, Germany, 53105
Sponsors and Collaborators
University Hospital, Bonn
Principal Investigator: Heiner K. Berthold, MD, PhD University of Bonn
  More Information

Responsible Party: Heiner K. Berthold, University of Bonn - Germany Identifier: NCT00872092     History of Changes
Other Study ID Numbers: BTO-0001
Study First Received: March 30, 2009
Last Updated: March 30, 2009

Keywords provided by University Hospital, Bonn:
small bowel
bacterial overgrowth

Additional relevant MeSH terms:
Malabsorption Syndromes
Intestinal Diseases
Gastrointestinal Diseases
Digestive System Diseases
Metabolic Diseases processed this record on March 29, 2017