Detection capacity of small intestine bacterial or methanogen overgrowth by lactose and fructose breath testing in the adult population

• Published in: Advances in laboratory medicine Vol. 5; no. 3; pp. 327 - 332
• Main Authors: Laserna Mendieta, Emilio José, Martín Dominguez, Verónica, Pérez Lucendo, Irene, Granero Cremades, Inmaculada, Ferreirós Martínez, Raquel, Álvarez Malé, Tomás, Sanz De Benito, María Ángeles, Santander, Cecilio
• Format: Journal Article
• Language: English
• Published: Germany De Gruyter 06.09.2024
• Subjects: exhaled breath test; fructose malabsorption/intolerance; intestinal methanogenic overgrowth; lactose malabsorption/intolerance; small intestine bacterial overgrowth; fructose malabsorption/intolerance; intestinal methanogenic overgrowth; lactose malabsorption/intolerance; small intestine bacterial overgrowth; exhaled breath test
• ISSN: 2628-491X; 2628-491X
• DOI: 10.1515/almed-2024-0115

Exhaled breath tests (BTs) are the main diagnostic method for fructose and lactose malabsorption/intolerance (FI and LI, respectively) and for detecting small intestine bacterial or methanogen overgrowth (SIBO/IMO). Although FI/LI-BTs may provide evidence of the presence of SIBO/IMO, there is limited literature evaluating their reliability for this purpose. The objective of this study was to assess the sensitivity and specificity of FI/LI-BTs in detecting SIBO and their concordance with SIBO-BTs in the identification of IMO. In this retrospective observational study, FI/LI-BTs and SIBO-BTs performed in the same patients within a period of 6 weeks were selected from 652 gas chromatography-based BTs. A total of 146 BTs from 67 eligible adult patients were identified. LI-BTs had higher specificity than FI-BT in detecting SIBO (93.8 % vs. 72.7 %). In contrast, FI-BTs showed higher sensitivity (60.0 % vs. 28.6 %) as FI was more frequently established in SIBO-positive patients (70 % vs. 29 %). With regard to IMO, concordance with LI-BT was 100 %, with a 27 % of false negatives on FI-BTs. Findings suggestive of SIBO or IMO on LI-BTs were highly consistent with those of SIBO-BTs. In contrast, the rate of false positives for SIBO and the rate of false negative for IMO on FI-BTs was 27 % in both cases.