SIBO, Immune Activation, and FGIDs in Children
Condition: Small Intestinal Bacterial Overgrowth; Irritable Bowel Syndrome; Functional Dyspepsia; Functional Abdominal Pain
MeSH terms: Irritable Bowel Syndrome; Dyspepsia; Abdominal Pain
Study type: Observational

Summary: 
      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 biomarkers to support the diagnosis of these FGIDs and novel targets
      for therapy, such as immune molecules and previously unrecognized bacterial phylotypes and
      species possibly contributing to disease pathogenesis, may be identified. Also, determining
      the reliability of the glucose breath hydrogen test vs. small bowel aspirate culture in the
      diagnosis of SIBO in this setting may enable the physician to avoid invasive and costly
      procedures in the diagnostic work-up of children with these FGIDs.
    


Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Patients (ages 4-17 years) presenting to the University of Texas-Houston Pediatric GI
        Clinic with complaints of abdominal pain and undergoing endoscopy (i.e.,
        esophagogastroduodenoscopy [EGD] and possibly colonoscopy) for further evaluation (at the
        discretion of the patient's gastroenterologist) will be screened for inclusion into the
        study at the time that the endoscopic evaluation is ordered by the patient's
        gastroenterologist.
      
Biospecimen description: 
      Small intestinal aspirate (fluid) will have bacterial DNA extracted