Impact of Oral-Cecal Transit Time on the Interpretation of Lactulose Breath Tests After RYGB: a Personalized Approach to the Diagnosis of SIBO
Traditionally, small intestinal bacterial overgrowth (SIBO) is diagnosed when there is an early peak in breath hydrogen or methane. Given unclear intestinal transit time in Roux-en-Y gastric bypass (RYGB) patients, it is unknown if the traditional approach at diagnosing SIBO is adequate in this patient population.
To assess oral-cecal transit time (OCTT) and its impact on the interpretation of breath tests in the diagnosis of SIBO in patients with RYGB.
This study was a retrospective review of prospectively collected data on RYGB patients who underwent testing for SIBO using lactulose breath test (LBT) with or without small bowel follow-through (SBFT) to assess OCTT. Outcomes of SIBO test based on LBT alone versus LBT with OCTT were compared using a chi-squared test.
Sixty-two of the 151 RYGB patients who underwent LBT underwent an additional SBFT to assess OCTT. Median OCTT was 60 min. Of these, 59.7% had OCTT shorter than 90 min. Based on LBT alone, 36/62 patients (58.1%) were classified as positive SIBO. When LBT results were combined with OCTT, 26/36 patients (72.2%) had hydrogen or methane rise within OCTT, suggesting 27.8% false positive rate. Patients with true positive SIBO based on LBT and OCTT had a higher response rate to antibiotics compared to those with false positive SIBO (78.3% vs. 33.3%, p = 0.03).
A personalized approach of combining LBT with SBFT to assess OCTT may improve the accuracy of SIBO testing and enhance clinical outcomes in patients with RYGB.
KeywordsRYGB Bariatric SIBO Bacterial overgrowth Breath test Bloating Abdominal pain
Pichamol Jirapinyo: Study design, data collection and analysis, drafting and revision of the manuscript
Tracy T. Makuvire: Data collection
William Y. Dong: Data collection
Walter W. Chan: Study design, study analysis
Christopher C. Thompson: Study design, critical revision of the manuscript
Compliance with Ethical Standards
The study was approved by the Institutional Review Board (IRB) (IRB Protocol Number, 2013P001597).
Conflict of Interest
The authors declare that they have no conflict of interest.
Ethical Approvement Statement
For this type of study, formal consent is not required.
Informed Consent Statement
Does not apply.
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