A Simplified Method Of Measuring Breath Hydrogen By End-Expiratory Sampling For Diagnosis Of Lactose Malabsorption

Summary1. The method of analysis of breath hydrogen by end-expiratory sampling was modified to allow immediate introduction of the alveolar air sample into a gas chromatograph.2. The modified method was used to study the absorption of 50g lactose in 20 healthy subjects without abdominal symptoms, 12 patients with normal lactase activity and 12 patients with low lactase activity. The results, expressed as peak hydrogen concentrations, were comparable to those of previous studies; 20 ppm was the threshold of abnormal hydrogen production. However, interpretation of the results may be facilitated if the measurement of breath hydrogen is coupled to sequential determination of capillary blood glucose.