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AzTrials

Small Intestine Bacterial OvergrowthPhase 2NCT07451171

Comparative Efficacy of Antibiotics for Small Intestine Bacterial Overgrowth in Bangladeshi Children

A Phase 2 study testing Trimethoprim-sulfamethoxazole (TMP/SMX), Metronidazole and Amoxicillin-Clavulanate (4:1 formulation) in people with Small Intestine Bacterial Overgrowth, run by University of Virginia at 1 site in Bangladesh.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

The purpose of this Phase IIa study is to identify the most effective antibiotic regimen to treat small intestine bacterial overgrowth (SIBO) in impoverished Bangladeshi children. Read more about this study

Who is it for?
Ages 1 year to 2 years
Conditions the study is for
Small Intestine Bacterial Overgrowth
What is being tested?
Trimethoprim-sulfamethoxazole (TMP/SMX), Metronidazole and Amoxicillin-Clavulanate (4:1 formulation)
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
60 participants
Where
1 siteBangladesh
Study dates
18 Apr 2026to 2 Dec 2026
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 1 year to 2 years
  • All sexes
  • No healthy volunteers
  • Child

Who may be able to join

  • Positive glucose hydrogen breath test (GHBT)
  • Weight-for-age Z score > -1
  • Length-for-age Z score > -1

Who cannot join

  • Presence of known chronic or congenital illness, including developmental delay
  • Presence of acute gastrointestinal illness in the preceding 14 days
  • Antibiotic use in the preceding 14 days
  • Previous adverse reaction to any of the three study medications or other drugs in the same antibiotic classes
  • Sibling previously enrolled in this study

Trial locations and contacts

1 site in 1 country.

Bangladesh1 site

  • International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b)

    Dhaka

Other trials in Bangladesh

About this study

Official title: A Phase II Trial to Prevent Linear Growth Stunting and Malnutrition in Impoverished Children From a Low-Income Country by Treating Small Intestine Bacterial Overgrowth

The purpose of this Phase IIa study is to identify the most effective antibiotic regimen to treat small intestine bacterial overgrowth (SIBO) in impoverished Bangladeshi children.

Being tested
Trimethoprim-sulfamethoxazole (TMP/SMX), Metronidazole, Amoxicillin-Clavulanate (4:1 formulation)
Keywords
environmental enteric dysfunction

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Trimethoprim-sulfamethoxazole (TMP/SMX)Drug

    8-10 mg/kg/day divided every 12 hours, with a maximum 160 mg/dose; dosing based on Trimethoprim

  • MetronidazoleDrug

    Administered alone: 20-30 mg/kg/day divided every 8 hours, with a maximum 750 mg/dose

    Co-administered with Trimethoprim-sulfamethoxazole: 35-50 mg/kg/day divided every 8 hours, with a maximum 750 mg/dose

  • Amoxicillin-Clavulanate (4:1 formulation)Drug

    20-40 mg amoxicillin/kg/day divided every 8 hours, with maximum daily dose of 1,500 mg

Study groups in NCT07451171
Study groupRoleWhat they receive
MetronidazoleExperimental14-day oral course
Receives: Drug: Metronidazole
Trimethoprim-sulfamethoxazole and MetronidazoleExperimental14-day oral course
Receives: Drug: Trimethoprim-sulfamethoxazole (TMP/SMX); Drug: Metronidazole
Amoxicillin-ClavulanateExperimental14-day oral course
Receives: Drug: Amoxicillin-Clavulanate (4:1 formulation)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Conversion to Glucose Hydrogen Breath Test (GHBT) Negativity at Day 15

    GHBT negativity will be defined as no breath hydrogen value ≥20 ppm over the patient's baseline during the course of the test. If any breath hydrogen value during the GHBT is >20 ppm over the patient's baseline, the test will be deemed positive.

    Measured: Day 15

Secondary outcomes (5)

  1. Conversion to GHBT Negativity at Day 45

    GHBT negativity will be defined as no breath hydrogen value ≥20 ppm over the patient's baseline during the course of the test. If any breath hydrogen value during the GHBT is >20 ppm over the patient's baseline, the test will be deemed positive.

    Measured: Day 45

  2. Average Glucose Hydrogen Breath Test Area Under the Curve

    Area under the hydrogen curve will be calculated at baseline, day 15, and day 45. An average of these values will be taken to construct this variable.

    Measured: Baseline, day 15, day 45

  3. Fecal Myeloperoxidase

    Fecal myeloperoxidase levels as measured by a commercially available ELISA kit.

    Measured: Baseline, day 15, day 45

  4. Fecal Neopterin

    Fecal neopterin levels as measured by a commercially available ELISA kit.

    Measured: Baseline, day 15, day 45

  5. Fecal Calprotectin

    Fecal calprotectin levels as measured by a commercially available ELISA kit.

    Measured: Baseline, day 15, day 45

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted5 Mar 2026
  2. Study start18 Apr 2026
  3. Primary completion21 Oct 2026
  4. Study completion2 Dec 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Outcomes assessor
Enrolment
60 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07451171
Sponsor's protocol ID
302580
Other IDs
1R01HD113733-01A1
Status last verified
Oct 2026
First submitted
27 Feb 2026
Last updated
2 Nov 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Tahan S, Melli LC, Mello CS, Rodrigues MS, Bezerra Filho H, de Morais MB. Effectiveness of trimethoprim-sulfamethoxazole and metronidazole in the treatment of small intestinal bacterial overgrowth in children living in a slum. J Pediatr Gastroenterol Nutr. 2013 Sep;57(3):316-8. doi: 10.1097/MPG.0b013e3182952e93.

    PubMed 23974062

  • Mello CS, Rodrigues MSDC, Filho HBA, Melli LCFL, Tahan S, Pignatari ACC, de Morais MB. Fecal microbiota analysis of children with small intestinal bacterial overgrowth among residents of an urban slum in Brazil. J Pediatr (Rio J). 2018 Sep-Oct;94(5):483-490. doi: 10.1016/j.jped.2017.09.003. Epub 2017 Oct 16.

    PubMed 29049893

  • Donowitz JR, Haque R, Kirkpatrick BD, Alam M, Lu M, Kabir M, Kakon SH, Islam BZ, Afreen S, Musa A, Khan SS, Colgate ER, Carmolli MP, Ma JZ, Petri WA Jr. Small Intestine Bacterial Overgrowth and Environmental Enteropathy in Bangladeshi Children. mBio. 2016 Jan 12;7(1):e02102-15. doi: 10.1128/mBio.02102-15.

    PubMed 26758185

  • Vonaesch P, Morien E, Andrianonimiadana L, Sanke H, Mbecko JR, Huus KE, Naharimanananirina T, Gondje BP, Nigatoloum SN, Vondo SS, Kaleb Kandou JE, Randremanana R, Rakotondrainipiana M, Mazel F, Djorie SG, Gody JC, Finlay BB, Rubbo PA, Wegener Parfrey L, Collard JM, Sansonetti PJ; Afribiota Investigators. Stunted childhood growth is associated with decompartmentalization of the gastrointestinal tract and overgrowth of oropharyngeal taxa. Proc Natl Acad Sci U S A. 2018 Sep 4;115(36):E8489-E8498. doi: 10.1073/pnas.1806573115. Epub 2018 Aug 20.

    PubMed 30126990

  • Pereira SP, Khin-Maung-U, Bolin TD, Duncombe VM, Nyunt-Nyunt-Wai, Myo-Khin, Linklater JM. A pattern of breath hydrogen excretion suggesting small bowel bacterial overgrowth in Burmese village children. J Pediatr Gastroenterol Nutr. 1991 Jul;13(1):32-8. doi: 10.1097/00005176-199107000-00006.

    PubMed 1833523

  • Mello CS, Tahan S, Melli LC, Rodrigues MS, de Mello RM, Scaletsky IC, de Morais MB. Methane production and small intestinal bacterial overgrowth in children living in a slum. World J Gastroenterol. 2012 Nov 7;18(41):5932-9. doi: 10.3748/wjg.v18.i41.5932.

    PubMed 23139610

  • dos Reis JC, de Morais MB, Oliva CA, Fagundes-Neto U. Breath hydrogen test in the diagnosis of environmental enteropathy in children living in an urban slum. Dig Dis Sci. 2007 May;52(5):1253-8. doi: 10.1007/s10620-006-9288-9. Epub 2007 Mar 20.

    PubMed 17372830

  • Gasbarrini A, Corazza GR, Gasbarrini G, Montalto M, Di Stefano M, Basilisco G, Parodi A, Usai-Satta P, Vernia P, Anania C, Astegiano M, Barbara G, Benini L, Bonazzi P, Capurso G, Certo M, Colecchia A, Cuoco L, Di Sario A, Festi D, Lauritano C, Miceli E, Nardone G, Perri F, Portincasa P, Risicato R, Sorge M, Tursi A; 1st Rome H2-Breath Testing Consensus Conference Working Group. Methodology and indications of H2-breath testing in gastrointestinal diseases: the Rome Consensus Conference. Aliment Pharmacol Ther. 2009 Mar 30;29 Suppl 1:1-49. doi: 10.1111/j.1365-2036.2009.03951.x.

    PubMed 19344474

  • Donowitz JR, Parikh HI, Taniuchi M, Gilchrist CA, Haque R, Kirkpatrick BD, Alam M, Kakon SH, Islam BZ, Afreen S, Kabir M, Nayak U, Colgate ER, Carmolli MP, Petri WA Jr. Increased Fecal Lactobacillus Is Associated With a Positive Glucose Hydrogen Breath Test in Bangladeshi Children. Open Forum Infect Dis. 2019 Jun 1;6(7):ofz266. doi: 10.1093/ofid/ofz266. eCollection 2019 Jul.

    PubMed 31281862

  • Pimentel M, Saad RJ, Long MD, Rao SSC. ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth. Am J Gastroenterol. 2020 Feb;115(2):165-178. doi: 10.14309/ajg.0000000000000501.

    PubMed 32023228

  • Donowitz JR, Pu Z, Lin Y, Alam M, Ferdous T, Shama T, Taniuchi M, Islam MO, Kabir M, Nayak U, Faruque ASG, Haque R, Ma JZ, Petri WA Jr. Small Intestine Bacterial Overgrowth in Bangladeshi Infants Is Associated With Growth Stunting in a Longitudinal Cohort. Am J Gastroenterol. 2022 Jan 1;117(1):167-175. doi: 10.14309/ajg.0000000000001535.

    PubMed 34693912

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Trimethoprim-sulfamethoxazole (TMP/SMX), Metronidazole and Amoxicillin-Clavulanate (4:1 formulation) in people with Small Intestine Bacterial Overgrowth, run by University of Virginia at 1 site in Bangladesh.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 2 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Bangladesh. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Conversion to Glucose Hydrogen Breath Test (GHBT) Negativity at Day 15 (time frame: Day 15). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07451171, which also lists 11 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Nov 2026.

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