Feasibility of a new diagnostic device to assess small intestinal dysbiosis in the routine clinical setting

Subjects will be patients presenting to the Department of Gastroenterology & Hepatology at the Princess Alexandra Hospital who require and are booked for an upper gastrointestinal endoscopy as part of the routine diagnostic work up of e.g. otherwise unexplained symptoms. The Atmo ingestible gas sensing capsule is a means of analysing microbiome function at the source of gas production by microbiota. Capsules will be ingested within 30 mins prior to endoscopy pre- and post-antimicrobial intervention (if the patients has had a treatment) to determine if it can be used to identify increased microbial load through gas detection, and to identify responders to therapy. If increased microbial load is determined through culture of aspiration during initial endoscopic procedure, randomised administration of either placebo or Rifaximin (550g) 1 capsule twice a day for 14 days. The placebo will be encapsulated maize starch and pregelatinised maize starch. The post-antimicrobial endoscopic procedure will be conducted at 6 weeks post the start of treatment. These hydrogen concentration results will be compared to the following conventional breath tests in a crossover study design. Immediately after the endoscopic procedure, the patient will undergo a FOS challenge recording hydrogen breath samples for 2 hours in 20 min intervals while they recover from the endoscopic procedure. A standard Glucose breath test will be performed by the patients at home not earlier that 8 hours after the endoscopic procedure.