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NCT Number: NCT01822470

Small Intestinal Bacterial Overgrowth: A Prospective Registry

The purpose of this study is to investigate the prevalence of small intestinal bacterial overgrowth (SIBO) in patients who will be undergoing an enteroscopy as an outpatient procedure with symptoms of functional dyspepsia. In addition, the investigators would like to identify the types of bacteria that are present in the small intestines in patients with SIBO and compare two different diagnostic tools: microbiologic culture and DNA sequencing of bacteria.

The aim is to compare the microbiota between patients with and without the clinical complications of SIBO

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Key information

Conditions

Functional Dyspepsia Body Weight Body Weight Changes Diarrhea Pathological Conditions, Signs and Symptoms Signs and Symptoms Signs and Symptoms, Digestive Small Intestinal Bacterial Overgrowth Weight Loss

Age range

18 year–90 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Indiana University Hospital

Indianapolis, Indiana, 46202, United States

About this study

Same as above

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

1.Study Subjects Inclusion Criteria i. All patients who are undergoing small bowel aspiration for suspected SIBO regardless etiology.

Exclusion criteria

i. Use of colon cleansing prep in the past 1 month ii. Treatment with antibiotics in the past 30 days (antibiotics are allowable for patients undergoing clinical indicated repeat aspiration to determine bacteria clearance) iii. Use of probiotics in the past 30 days iv. Contraindication for upper endoscopy for any reason v. Prisoners vi. Pregnant vii. Unable to give own informed consent

2 Control Subjects Inclusion Criteria i. Patients who are undergoing double balloon enteroscopy or upper enteroscopy for another medical reason.

Exclusion criteria

i. Diagnosis of SIBO ii. Diagnosis of functional dyspepsia iii. Established risk factors for SIBO (ANY of the following)

  • Connective tissue disorder (scleroderma, polymyositis, mixed connective tissue disease, or systemic lupus
  • Resection of ileocecal valve for any reason
  • Chronic intestinal pseudo-obstruction
  • Small bowel blind limb, diverticulum or fistula
  • Surgery with decreased gastric acid exposure for small bowel a. Gastric surgery with vagotomy (Bilroth I, Bilroth II, vagotomy/pyloroplasty) or gastric bypass iv. Use of colon cleansing prep in the past 1 month v. Use of antibiotics in the past 30 days vi. Use of probiotics in the past 30 days vii. Contraindication for upper endoscopy for any reason viii. Prisoners ix. Pregnant x. Unable to give own informed

Treatment and study plan

Primary outcomes

  1. To determine the predictors for SIBO in patients with functional dyspepsia, who do not have the established risk factors for SIBO

    Time frame: two years

    In this population, prevalence of potential predictors of SIBO will be compared between subjects with and without a diagnosis of Gram Negative Bacteria SIBO

Secondary outcomes

  1. A registry of patients undergoing proximal jejunal aspiration for suspected small intestinal bacterial overgrowth

    Time frame: Two years

    A prospective registry will be created for all subjects who are undergoing jejunal aspirate for clinical indications. Private health information will be excluded from the data registry. Data collected for the registry will include:

    • Demographics
    • Patient Assessment of Gastrointestinal Disorders-Symptom Severity Index total and subscale scores
    • Presence of functional gastrointestinal disorders
    • Established risk factors of gram negative small intestinal bacterial overgrowth.
    • Established risk factors of upper respiratory tract small intestinal bacterial overgrowth

  2. The demographics, clinical history, and symptoms in patients with and without SIBO

    Time frame: One day

    Demographics 2. Patient Assessment of Gastrointestinal Disorders-Symptom Severity Index total and subscale scores 3. Presence of functional gastrointestinal disorders 4. Established risk factors of gram negative small intestinal bacterial overgrowth.

    • Established risk factors of upper respiratory tract small intestinal bacterial overgrowth

  3. Characterize the clinical differences between small intestinal bacterial overgrowth by upper respiratory tract bacteria and small intestinal bacterial overgrowth by gram-negative bacilli bacteria

    Time frame: One day

    clinical differences between small intestinal bacterial overgrowth by upper respiratory tract bacteria

  4. Compare the composition between luminal and mucosal bacteria in the proximal small bowel

    Time frame: One day

    Compare the results of bacteria species isolated from molecular polymerase chain reaction identification between luminal aspiration samples and mucosa biopsy samples.

Sponsors and collaborators

Lead sponsor

Indiana University

Other

Collaborators

  • Progenity, Inc.

Registry information

Acronym: SIBO

Important dates

Study start
2013
Primary completion
2026
Study completion
2026
First posted
Apr 2, 2013
Registry last updated
Jun 16, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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