Small Intestinal Bacterial Overgrowth: A Prospective Registry (SIBO)

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

Study Overview

• Status: Enrolling by invitation
• Conditions: Functional Dyspepsia; Small Intestinal Bacterial Overgrowth

Detailed Description

Same as above

• Study Type: Observational
• Enrollment (Estimated): 200

Contacts and Locations

Study Locations

• United States
  • Indiana
    • Indianapolis, Indiana, United States, 46202
      • Indiana University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

a. All adult patients who are undergoing small bowel aspiration for suspected SIBO regardless etiology

Description

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)

1. Connective tissue disorder (scleroderma, polymyositis, mixed connective tissue disease, or systemic lupus
2. Resection of ileocecal valve for any reason
3. Chronic intestinal pseudo-obstruction
4. Small bowel blind limb, diverticulum or fistula
5. 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

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Study group; a. Study Subjects will be recruited from patients who are already undergoing upper enteroscopy and aspiration for diagnosis of SIBO.
Control group; b. Control Subjects will be recruited from patients who are already undergoing a double balloon enteroscopy or upper enteroscopy for another medical reason

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To determine the predictors for SIBO in patients with functional dyspepsia, who do not have the established risk factors for SIBO	In this population, prevalence of potential predictors of SIBO will be compared between subjects with and without a diagnosis of Gram Negative Bacteria SIBO	two years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
A registry of patients undergoing proximal jejunal aspiration for suspected small intestinal bacterial overgrowth	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	Two years
The demographics, clinical history, and symptoms in patients with and without SIBO	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. 5. Established risk factors of upper respiratory tract small intestinal bacterial overgrowth	One day
Characterize the clinical differences between small intestinal bacterial overgrowth by upper respiratory tract bacteria and small intestinal bacterial overgrowth by gram-negative bacilli bacteria	clinical differences between small intestinal bacterial overgrowth by upper respiratory tract bacteria	One day
Compare the composition between luminal and mucosal bacteria in the proximal small bowel	Compare the results of bacteria species isolated from molecular polymerase chain reaction identification between luminal aspiration samples and mucosa biopsy samples.	One day

Collaborators and Investigators

• Sponsor: Indiana University
• Collaborators: Progenity, Inc.
• Investigators: Principal Investigator: John Wo, MD, Indiana University Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 7, 2013
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: March 25, 2013
• First Submitted That Met QC Criteria: March 27, 2013
• First Posted (Estimated): April 2, 2013

Study Record Updates

• Last Update Posted (Actual): June 16, 2026
• Last Update Submitted That Met QC Criteria: June 15, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: diarrhea; weight loss; functional dyspepsia; bloating; epigastric pain syndrome; post prandial distress syndrome; small bowel bacteria overgrowth; post prandial fullness
• Additional Relevant MeSH Terms: Body Weight; Signs and Symptoms, Digestive; Body Weight Changes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Weight Loss; Diarrhea
• Other Study ID Numbers: 1209009531

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• product manufactured in and exported from the U.S.: No