Breath Ammonia Method for H. Pylori Detection: Phase II

The objective is to evaluate the utility of a breath ammonia sensing device. In this study we will assess the effect of H. pylori infection on breath ammonia levels by measuring whether there is a change in the pattern or quantity of breath ammonia seen in H. pylori positive patients compared to H. pylori negative patients.

Healthy volunteers will undergo testing for H. pylori infection using a 14-C urea breath test, and the results will be compared to an experimental ammonia breath test. The breath sample will be collected by an investigational device that the patient will be exposed to consisting of a plastic mouth-piece which is attached to a T-tubing section having a side-arm port through which a fiberoptic ammonia sensor is inserted inside the tube. To meet the Phase II specific aim, the scope of the clinical trials is expanded addressing the following specific objectives: Test refinements of the sensing system (hardware, software, & breath test device) Determine whether a urea dose-response effect exists following urea ingestion, Define the optimal cutoff values for expired breath ammonia to allow optimal discrimination of H. pylori infected vs. uninfected persons. Determine the appropriate time interval for breath ammonia testing following urea ingestion. Determine whether there is a change in breath ammonia level after H. pylori treatment.

Determination of whether breath ammonia measurement allows determination of successful H. pylori treatment.

Inclusion Criteria: Adult volunteers not meeting exclusion criteria Exclusion Criteria: Known cirrhosis of the liver Renal insufficiency (BUN greater than 40 mg/dl, Creatinine greater than 2.0 mg/dl). Prior gastric resection Severe chronic obstructive pulmonary disease (Forced expiratory volume in 1 second less than 1.5 L) Patients unwilling or unable to discontinue proton pump inhibitors for 2 weeks prior to scheduled 14C or non-isotopic urea breath testing Patients who have received antibiotics or bismuth within the preceding month. Patients unwilling or unable to give informed consent Pregnant women (14C urea breath test is not approved for use in pregnant women) Age less than 21 years (14C urea breath test is not approved for use in children)