Irritable Bowel Syndrome clinical trials at University of California Health

The study will investigate the relationship between fecal bile acids, short-chain fatty acids (SCFAs), and the gut microbiota in irritable bowel syndrome (IBS). The central hypothesis of this study is that specific shifts in the GI microbiome composition correlate with altered colonic SCFAs and BAs and contribute to IBS symptoms. Primary aims include: (a) identifying GI microbiome signatures in IBS subtypes (IBS-C and IBS-D) and matched controls, and test if microbiome signatures in these groups correlate with fecal SCFAs and bacterial fermentation of an indigestible carbohydrate (inulin) after a dietary challenge (fecal inulin), and (b) determining if GI microbiome signatures in IBS subtypes and controls correlate with fecal BAs or markers of SCFA production (fecal SCFAs or inulin) and test if BAs correlate with fecal SCFAs or inulin. The target population is adults ages 18-65 years meeting Rome IV criteria for IBS (both diarrhea- and constipation-predominant, IBS-D and IBS-C) and asymptomatic controls. Primary outcomes will be fecal bile acid excretion and profile, short-chain fatty acid excretion and profile, colonic transit, and fecal microbiota. Secondary outcomes will be stool characteristics based on responses to validated bowel diaries. Stool samples will be collected from participants during the last 2 days of a 4-day 100 g fat diet and split into 3 samples for fecal microbiota, SCFA, and bile acid analysis.

Background. Abdominal distention is produced by an abnormal somatic postural tone. The authors developed an original biofeedback technique. In a randomized, placebo-controlled trial the authors demonstrated the superiority of biofeedback over placebo for the treatment of abdominal distention. However, the technique is technically complex and unpractical. Aim. To prove the efficacy of a noninstrumental biofeedback technique, transmitted by a standard training program, for the treatment of abdominal distension in different centers. Selection criteria. Episodes of visible abdominal distension. Intervention. Patients will be randomized into biofeedback and placebo groups. Three sessions of either biofeedback or placebo intervention will be performed during the first 3 weeks of the intervention period. Biofeedback: Patients will be taught to control abdominal and thoracic muscular activity by providing instructions using an original video support. In each center one operator will receive a standard training on how to deliver the noninstrumental biofeedback treatment. Patients will be instructed to perform the same exercises before and after breakfast, lunch and dinner during the 4-week intervention period. Placebo: Sham measurements of abdominal and thoracic motion will be performed, and a pill of placebo containing 0.21 g glucose will be administered; patients will be instructed to take a pill of placebo before breakfast, lunch and dinner during the 4-week intervention period.