Study Compares Two Tests for Diagnosing Small Intestine Bacterial Problems
- Authors
- Giulia Scalese, Luca Spina, Lucia Gallucci, Alessandra Cesarini, Emanuela Ribichini, Maddalena Diofebi, Ivan Tattoli, Lucia Pallotta, Anna Citarella, Carola Severi
- Journal
- Journal of Clinical Medicine
- Year
- 2025
- DOI
- 10.3390/jcm14248920
- Study Type
- Human
- Outcome
- Neutral
- Peer Reviewed
- Yes
- Country
- Italy
- Health Condition
- Small Intestinal Bacterial Overgrowth
- Body System
- Digestive
TL;DR
Breath testing showed that methane-producing microbes in the small intestine generate methane earlier than hydrogen, reflecting differences in microbial activity and gas metabolism.
Key Finding
The glucose breath test is more reliable for diagnosing small intestinal microbial overgrowth than the lactulose breath test, primarily because the lactulose test has lower specificity (meaning it produces more false positives).
Summary
This study compared two breath tests used to diagnose small intestinal microbial overgrowth (SIMO)—a condition where too many bacteria or methane-producing organisms grow in the small intestine. Researchers tested 564 patients using either a glucose breath test, a lactulose breath test, or both. They found that the glucose breath test was more reliable overall, though both tests performed similarly when looking for methane-producing organisms specifically. Symptoms alone could not predict which type of overgrowth a patient had.
Practical Takeaway
This study addresses diagnostic methodology rather than hydrogen water itself and does not evaluate hydrogen water as a treatment. For anyone considering breath testing for suspected small intestinal issues, this research suggests that the type of breath test used matters—glucose-based testing may be more accurate than lactulose-based testing. However, this study does not provide evidence about hydrogen water's effects on these conditions.
Abstract (excerpt)
Background/Objectives: Small intestinal microbial overgrowth (SIMO), including both small intestinal bacterial overgrowth (SIBO) and intestinal methanogen overgrowth (IMO), is commonly diagnosed using non-invasive breath tests, whose diagnostic performance and criteria remain inconsistent. This…