In order to diagnose an increased bacterial density in the small intestine (e.g small intestinal bacterial overgrowth) metabolic activity of the microbiota colonising the small intestine is measured by exposing these bacteria with readily fermentable carbohydrates and measure subsequently (e.g. for 2 hrs) the change of the concentration of hydrogen (H2) and/or methane in the exhaled breath that results from carbohydrate fermentation in the small intestine. This is the principle of existing breath hydrogen tests, but they are poor at distinguishing where in the intestine the H2 is being produced, and their sensitivity is diminished by 'noise' in the breath H2 as a consequence of hydrogen or methane producing bacteria in the colon and this is frequently observed in the routine clinical setting. These shortcomings can be theoretically overcome by using the Atmo Gas CapsuleR which measures after ingestion gas concentrations during gastrointestinal transit in the lumen of the gut. As a consequence at the site of fermentation parts per hundred can be measured, rather than the parts per million (ppm) when methane or hydrogen are measured in the exhaled breath. An additional advantage is that the location of the capsule is known, and therefore the source of gas production from increased bacterial load can be determined. Preliminary studies using the gas capsule have shown good correlation of patterns of breath H2 with those of regional H2 patterns generated by the gas-sensing capsule. In fact, the capsule demonstrated far greater sensitivity in measuring H2 production and a vastly superior signal-to-noise ratio in response to a fermentable load than breath testing. Hence, investigating the utility of the gas-sensing capsule as a means for 'direct' assessment of microbial density presents an opportunity to overcome the shortcomings associated with the current breath test.
The purpose of this study is to determine if the gas-sensing capsule can be used to identify increased numbers and a change of the composition of microbiota or microorganisms in the gut to assess small intestinal dysbiosis