Simultaneous detection of hydrogen and methane in breath for the diagnosis of small intestinal bacterial overgrowth by fast gas chromatography

Abstract

The hydrogen and methane breath test has been widely used in the diagnosis of SIBO (small intestinal bacterial overgrowth), which is noninvasive and convenient with good accuracy. However, most studies use commercial GC-MS to analyze breath components which requires complex operation and has a high cost, while the most common simplified devices only have a single function with some drawbacks. This study proposes a convenient, small-sized and multi-functional fast gas chromatograph (Fast GC) with a low detection limit and sufficient resolution to simultaneously determine hydrogen and methane concentrations, corrected using the carbon dioxide concentration, in breath. The system can eliminate the interference caused by dilution with outside gases, the breathing mode of the patient and other factors of alveolar gas. The detection range of the Fast GC system was 2–200 ppm, the resolution was 1 ppm, the precision was less than 10%, and the preheating time was significantly shortened to 2 hours, as well as the size being reduced to 40 cm × 30 cm × 15 cm. Two SIBO diagnostic models were established and samples from forty-seven healthy people and patients were collected and analyzed by our system. This method has the advantages of high specificity, and non-invasive and simple operation, so that it can be used for the diagnosis of increasing volumes of clinical and domestic patients.