Breath ammonia measurement in Helicobacter pylori infection.

Our aim was to define the utility of breath ammonia measurement in assessing Helicobacter pylori infection. Volunteers breathed into a device containing three fiberoptic NH3 sensors at baseline and after ingesting 300 mg of urea. Breath ammonia levels were compared to the [14C]urea breath test. Thirteen subjects were tested. Before urea ingestion, H. pylori-positive subjects had significantly lower breath ammonia levels than negative subjects (mean +/- SD, 0.04 ppm +/- 0.09 vs 0.49 ppm +/- 0.24, P = 0.002) and had a significantly greater increases in breath ammonia after urea ingestion (range 198-1,494% vs 6-98%). One H. pylori-positive subject underwent treatment and breath ammonia levels shifted from the pattern seen in positive subjects to that seen in negative subjects. In conclusion, breath ammonia measurement for H. Pylori-positive and negative subjects showed distinct patterns. Breath ammonia measurement may be feasible as a diagnostic test for H. pylori.