The clinical value of breath ammonia determination in patients with irritable bowel syndrome.

UNLABELLED: Gastrointestinal tract is the major source of ammonia (NH3). NH3 is produced by bacterial hydrolysis of urea as well as by bacterial protein deamination. The intensity of this process depends on protein intake and the amount of gut bacteria.

AIM: The aim of the study was to assess the level of the fasting breath ammonia in patients with irritable bowel syndrome (IBS) in relation to the results of lactulose hydrogen breath test (LHBT) and to clinical form of this syndrome before and after 14-days rifaximin treatment at daily dose of 1200 mg.

MATERIALS AND

METHODS

The study was conducted in 120 subjects, including 40 healthy people (Controls, group I), 40 patients with IBS and predominant diarrhea (group II, IBS-D), and 40 patients with IBS and predominant constipation (group III, IBS-C). The lactulose breath test (LHBT) and ammonia breath test (ABT) were performed. Diagnosis of IBS was based on Rome IV Criteria. The severity of abdominal symptoms was assessed using the Gastrointestinal Symptom Rating Scale (GSRS-IBS).

RESULTS

The basic level of ammonia in expired air in control group I was 5.2 ± 1.6 ppm, in group II - 20.8 ± 5.1 ppm (p< 0.001), and in group III - 10.4 ± 3.2 ppm (p< 0.001). Positive correlation was found between breath ammonia level and the results of LHBT in both groups with IBS. After 14-days rifaximin treatment at daily dose of 1200 mg the results of LHBT and breath ammonia significantly decreased in both groups. At the same time abdominal ailments subsided or significantly reduced.

CONCLUSIONS

The determination of breath ammonia may be useful as biomarker of dysbiosis in patients with irritable bowel syndrome, especially in questionable results of hydrogen breath test.