Hydrogen (H2) Breath Test and Gastric Bacteria in Acid-Secreting Subjects and in Achlorhydric and Postgastrectomy Patients before and after Antimicrobial Treatment

Abstract

Sixteen patients with pentagastrin-fast achlorhydria and 12 patients who had undergone Billroth II gastrectomy (at least 3 years previously) were compared with 10 acid-secreting volunteers and 13 patients with endoscopically proven peptic disease. The concentration and type of gastric bacteria were analysed in achlorhydrics, Billroth II patients, and patients with peptic disease. A 6-h hydrogen (H₂) breath test after a standardized meal was performed in all subjects. The mean concentration of gastric bacteria was significantly higher in achlorhydrics and Billroth II patients than in patients with peptic disease. End-expiratory H₂ excretion was elevated in achlorhydrics and Billroth II patients to levels significantly exceeding those of acid-secreting volunteers and patients with peptic disease. In achlorhydrics, total bacterial concentration in gastric juice was correlated to H₂ excretion between 60 and 180 min after the meal. Treatment of achlorhydric and postgastrectomy patients with trimethoprim/ sulphamethoxazole lowered H₂ breath concentrations in both groups and reduced symptoms in achlorhydrics. Elevated end-expiratory H₂ levels after a test meal indicate upper gastrointestinal bacterial overgrowth in achlorhydrics and in postgastrectomy patients.