Small intestinal bacterial overgrowth (SIBO) is defined as a condition in which an abnormally high amount of coliform bacteria is present in the small bowel and results in premature anaerobic fermentation of carbohydrates before reaching the colon. Commonly recognized causes include gastric achlorhydria, post-surgical bowel stasis, gastrocolic/coloenteric fistulas, and motility disorders leading to bowel stasis.. The current "gold standard" for the diagnosis of SIBO, is a breath test that measures the concentration of hydrogen in response to lactulose, a carbohydrate that is only metabolized by bacteria. However, its accuracy is only about 50% and therefore it is not a very useful test, leading most physicians to treat these patients empirically based on clinical suspicion alone. The purpose of this study is to evaluate the clinical utility of a portable medical device called AIRE, an over-the-counter, commercially available handheld breath analyzer that measures exhaled hydrogen content.

Small intestinal bacterial overgrowth (SIBO) is defined as a condition in which an abnormally high amount of coliform bacteria is present in the small bowel and results in premature anaerobic fermentation of carbohydrates before reaching the colon. Commonly recognized causes include gastric achlorhydria (i.e. due to longstanding proton pump inhibitor (PPI) use), post-surgical bowel stasis, and gastrointestinal motility disorders leading to bowel stasis. Although SIBO is commonly suspected, a major limitation in the field is the lack of a highly accurate test for SIBO. The current gold standard relies on the demonstration of an early rise in breath hydrogen concentration in response to an orally ingested carbohydrate (commonly, lactulose) but its accuracy is about 50%. This may be because it is a one-time snapshot with an artificial substrate. Further, it has to be performed in a clinic, takes up to 5 hours and is relatively expensive. The purpose of this study is to evaluate the clinical utility of a portable medical device called AIRE, which is a validated and commercially available handheld breathalyzer that measures hydrogen content in the breath and connects via Bluetooth to an associated smartphone application to provide immediate results and visual feedback after use.

Inclusion Criteria:

• Adults (18 years of age or older)
• Chronic (>3 months) GI symptoms such as nausea, bloating, distention, altered bowel movements, weight loss or abdominal pain with no structural cause other than scleroderma.
• Clinical diagnosis of SIBO by patient's gastroenterologist with plans to obtain a lactulose hydrogen breath test.
• Ability to tolerate oral intake.
• Ability to undergo the LHBT.
• Access to a smartphone with Bluetooth capability

Exclusion Criteria:

• History of current or recent antibiotic use within the last 30 days
• History of inflammatory bowel disease
• Currently following a restrictive diet (for example low Fermentable Oligo-, Di-, Mono-saccharides And Polyols (FODMAP) diet)
• Unable to tolerate oral intake

Up to 1 month of study participation