Usefulness of the hydrogen breath test in patients with functional dyspepsia

Introduction
The pathogenesis of functional dyspepsia is complex and not well understood. Therefore, in this disease there should be considered involvement of different pathogenic factors, including intestinal bacteria.

Aim
To evaluate the results of the hydrogen breath test in relation to the clinical picture of functional dyspepsia.

Material and methods
The study included 40 healthy subjects (group I), 72 patients with postprandial distress syndrome (PDS, group II), and 84 patients with epigastric pain syndrome (EPS, group III). The diagnosis of functional dyspepsia was based on Rome Criteria IV. The urea breath test (13C-UBT) and lactulose hydrogen breath test (LHBT) were performed in all subjects. Patients with a positive urea breath test were excluded from the study. Patients with a positive LHBT test were assigned to antibiotic therapy (1200 mg daily for 14 days). Before treatment and 6 weeks after the end of antibiotic therapy the LHBT was performed, and severity of dyspeptic symptoms was assessed using a 10-points visual analogue scale.

Results
A positive LHBT test was found in 35 (48.6%) patients in the group with PDS, and in 40 (47.6%) patients with EPS (p > 0.05). A positive correlation between the results of the LHBT test and severity of dyspeptic symptoms was found in both group (p < 0.001). After treatment with rifaximin the mean LHBT result and the index of severity of dyspeptic complaints were significantly decreased (p < 0.001).

Conclusions
Quantitative and/or qualitative changes in the gut microbiota may be the cause of functional dyspepsia.