SIBO, Immune Activation, and FGIDs in Children

PURPOSE: This study will evaluate the relationships between small intestinal bacterial overgrowth (SIBO), immune activation, inflammation, and symptoms in pediatric abdominal pain-related functional gastrointestinal disorders (FGIDs), i.e., irritable bowel syndrome (IBS), functional dyspepsia (FD), \& functional abdominal pain (FAP), to better understand the role of SIBO in their pathogenesis. DESIGN \& PROCEDURES: Cross-sectional study. Subjects: Patients followed at the UT-Houston Pediatric GI clinic, aged 4-17 years, undergoing endoscopic evaluation of abdominal pain, meeting Rome III diagnostic criteria for IBS, FD, or FAP, without evidence of an organic etiology of abdominal pain upon routine laboratory, radiologic, endoscopic, histologic evaluation. Sample Size: At least 30 patients, ≥ 15 with SIBO (i.e., positive small bowel aspirate culture and/or glucose breath hydrogen test), and ≥15 without SIBO. Sample Materials: Small bowel biopsies and aspirates, serum, breath samples, symptom questionnaire responses. Measures: 1) Immune activation \& inflammation - measured by serum cytokine levels \& small intestinal tissue inflammatory cell infiltration \& cytokine levels. 2) Symptoms - measured by Abdominal Pain Index, Wong-Baker FACES™ Pain Rating Scale, Questionnaire on Pediatric Gastrointestinal Symptoms - Rome III Version. 3) Small bowel microbiota analysis - assessed by 454 pyrosequencing. RISKS \& POTENTIAL BENEFITS: Aside from the risks associated with routine endoscopy with biopsies, which would occur even without study enrollment, the risks associated with serum collection, one extra biopsy specimen collection, small bowel aspirate collection, completion of pain scales/ questionnaires, and the glucose breath hydrogen test for the purposes of the study are minimal. POTENTIAL IMPACT: This study should yield valuable information regarding the relationships between SIBO, immune activation, inflammation, and symptoms in pediatric IBS, FD, and FAP. Potential bio