Impact of Oral-Cecal Transit Time on the Interpretation of Lactulose Breath Tests After RYGB: a Personalized Approach to the Diagnosis of SIBO

• Published in: Obesity surgery Vol. 29; no. 3; pp. 771 - 775
• Main Authors: Jirapinyo, Pichamol, Makuvire, Tracy T., Dong, William Y., Chan, Walter W., Thompson, Christopher C.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.03.2019; Springer Nature B.V
• Subjects: Breath tests; Breath Tests - methods; Dysbiosis - diagnosis; Dysbiosis - metabolism; Gastric Bypass - adverse effects; Gastrointestinal Transit - physiology; Humans; Intestinal Diseases - diagnosis; Intestinal Diseases - etiology; Intestinal Diseases - metabolism; Lactulose - analysis; Lactulose - metabolism; Medicine; Medicine & Public Health; Original Contributions; Retrospective Studies; Surgery; Breath test; RYGB; Bariatric; Bacterial overgrowth; SIBO; Abdominal pain; Bloating
• ISSN: 0960-8923; 1708-0428
• DOI: 10.1007/s11695-018-3575-3

Background 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. Aim 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. Methods 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. Results 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). Conclusion 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.