The safety and sensitivity of a telemetric capsule to monitor gastrointestinal hydrogen production in vivo in healthy subjects: a pilot trial comparison to concurrent breath analysis

Background Intestinal gases are currently used for the diagnosis of disorders including small intestinal bacterial overgrowth and carbohydrate malabsorption. Aim To compare the performance of measuring hydrogen production within the gut directly with the telemetric gas-sensing capsule with that of indirect measurement through breath testing. Methods Using standard breath testing protocols, the capsules and breath tests were simultaneously evaluated in a single-blinded trial in 12 healthy subjects. Eight received a single dose of 1.25-40g inulin and four 20 or 40g glucose. Safety and reliability of the capsules were also assessed. Results There were no reported adverse events. All capsules were retrieved and operated without failure. Capsule measurements were in agreement with breath test measurements in magnitude but not in timing; minimal hydrogen production was observed after glucose ingestion and capsule measurements correlated with breath hydrogen after ingestion of 40g inulin. A dose-dependent increase in concentration of hydrogen was observed from the capsule following ingestion of inulin as low as 1.25g compared with >10g for breath measurements. Specifically, the capsule measured >3000 times higher concentrations of hydrogen compared to breath tests, resulting in a signal-to-noise ratio of 23.4 for the capsule compared to 4.2 for the breath test. Conclusions The capsule showed high sensitivity and signal-to-noise ratio in measuring luminal hydrogen concentrations, provided information on the site of intestinal gas production, and demonstrated safety and reliability. The capsule has potential for improving diagnostic precision for disorders such as small intestinal bacterial overgrowth.