Breath tests for the non-invasive diagnosis of small intestinal bacterial overgrowth: A systematic review with meta-analysis

Giuseppe Losurdo, Gioacchino Leandro, Enzo Ierardi, Francesco Perri, Michele Barone, Mariabeatrice Principi, Alfredo Di Leo

Research output: Contribution to journalReview articlepeer-review


Background/Aims Small intestinal bacterial overgrowth (SIBO) diagnosis is usually based on non-invasive breath tests (BTs), namely lactulose BT (LBT) and glucose BT (GBT). However, divergent opinions and problems of parameter standardization are still controversial aspects. We aim to perform a meta-analysis to analyze diagnostic performance of LBT/GBT for SIBO diagnosis. Methods We searched in main literature databases articles in which SIBO diagnosis was achieved by LBT/GBT in comparison to jejunal aspirate culture (reference gold standard). We calculated pooled sensitivity, specificity, positive, and negative likelihood ratios and diagnostic odd ratios. Summary receiver operating characteristic curves were drawn and pooled areas under the curve were calculated. Results We selected 14 studies. Pooled sensitivity of LBT and GBT was 42.0% and 54.5%, respectively. Pooled specificity of LBT and GBT was 70.6% and 83.2%, respectively. When delta over baseline cut-off > 20 H2 parts per million (ppm) was used, GBT sensitivity and specificity were 47.3% and 80.9%; when the cutoff was other than and lower than > 20 ppm, sensitivity and specificity were 61.7% and 86.0%. In patients with abdominal surgery history, pooled GBT sensitivity and specificity gave the impression of having a better performance (81.7% and 78.8%) compared to subjects without any SIBO predisposing condition (sensitivity = 40.6% and specificity = 84.0%). Conclusions GBT seems to work better than LBT. A cut-off of delta H2 expired other than and lower than > 20 ppm shows a slightly better result than > 20 ppm. BTs demonstrate the best effectiveness in patients with surgical reconstructions of gastrointestinal tract.

Original languageEnglish
Pages (from-to)16-28
Number of pages13
JournalJournal of Neurogastroenterology and Motility
Issue number1
Publication statusPublished - 2020


  • Breath tests
  • Glucose
  • Hydrogen
  • Lactulose
  • SIBO

ASJC Scopus subject areas

  • Clinical Neurology
  • Gastroenterology


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