Study of the Esophageal String Test (EST) for the Diagnosis of Helicobacter Pylori

September 3, 2026 updated by: National Institute of Allergy and Infectious Diseases (NIAID)

A Pilot Prospective Study of the Esophageal String Test (EST) for the Diagnosis of Helicobacter Pylori

Background:

Helicobacter pylori is a bacterium that infects the lining of the stomach and intestines. It can cause peptic ulcers, cancers, and infections. Current methods of diagnosing H. pylori infections have limitations. Researchers want to test a new method of testing for H. pylori.

Objective:

To compare the esophageal string test (EST) to standard tests for detecting H. pylori infection.

Eligibility:

People aged 18 years or older with persistent H. pylori infection.

Design:

Participants will have 3 or 4 clinic visits over 2 to 4 months.

Screening visit: Participants will have a physical exam. They will provide a stool sample.

Baseline visit: Participants will have blood tests. Then they will have the EST: One end of a string will be taped to the outside of their cheek; the other end will be packed into a capsule. Participants will swallow the capsule, and the string will unwind down their throat into their stomach. The string will be left in for at least 1 hour. Then researchers will gently pull out the string. The fluids soaked into the string will be studied. Some participants will be prescribed antibiotics.

Follow-up visit 1: Participants whose H. pylori infection was cured by the antibiotics may leave the study. Those who are still infected will have an endoscopy: A flexible tube will be inserted down the throat and into the stomach. It will take tissue samples from the stomach lining. These participants will then receive antibiotics again.

Follow-up visit 2: The physical exam, blood test, and stool sample will be repeated.

...

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

Study Description:

Adults with active Helicobacter pylori infection will undergo an esophageal string test (EST). The gastric portion of the string will be used for detection of H. pylori by polymerase chain reaction (PCR), as well as assessment of resistance genes to clarithromycin, levofloxacin, and metronidazole. Participants will be treated per current American Gastroenterological Association (AGA) guidelines. A stool antigen test for H. pylori will be performed 4 weeks after completion of therapy to assess cure. Participants who have failed >=2 courses of therapy will undergo endoscopy with resistance testing per AGA recommendations. Patients will be offered antibiotic therapy based on the EST results and will have a repeat H. pylori stool antigen test 4 weeks after completion of therapy.

Primary Objective:

To assess the sensitivity of the gastric portion of the EST in detecting H. pylori infection.

Secondary Objectives:

To assess the ability of the gastric portion of the EST in detecting antimicrobial resistance to clarithromycin, levofloxacin, and metronidazole.

Primary Endpoint:

Proportion of the study population identified positive for H. pylori in EST eluates by PCR.

Secondary Endpoint:

Detection of H. pylori antibiotic resistance genes in EST eluates.

Study Type

Interventional

Enrollment (Actual)

5

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Maryland
      • Bethesda, Maryland, United States, 20892
        • National Institutes of Health Clinical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

  • INCLUSION CRITERIA:

In order to be eligible to participate in this study, an individual must meet all of the following criteria:

  • Aged >=18 years
  • Diagnosed with H. pylori infection (by endoscopy, stool antigen, or urea breath testing)
  • Agreement to adhere to lifestyle considerations throughout study duration
  • Ability of participant to provide informed consent

EXCLUSION CRITERIA:

An individual who meets any of the following criteria will be excluded from participation in this study:

  • Pregnancy or lactation
  • Use of antibiotics with activity against H. pylori within 4 weeks of enrollment
  • Inability to swallow pills
  • Biopsy-proven high grade dysplastic Barrett s esophagus, active peptic ulcer disease, recent (within 4 weeks) upper GI bleed, and/or history of Zollinger Ellison syndrome or gastric bypass surgery

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: EnteroTracker(R) EST
Esophageal string test device consists of a gelatin-coated capsule with a collection string wrapped inside.
Diagnostic test: EnteroTracker(R) EST
The device consists of a gelatin-coated capsule with a collection string wrapped inside.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Proportion of the study population identified positive for H. pylori in EST eluates by PCR.
Time Frame: Baseline
To assess the sensitivity of the gastric portion of the EST in detecting H. pylori infection.
Baseline

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Detection of H. pylori antibiotic resistance genes in EST eluates.
Time Frame: Baseline
To assess the ability of the gastric portion of the EST in detecting antimicrobial resistance to clarithromycin, levofloxacin, and metronidazole.
Baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Institute of Allergy and Infectious Diseases (NIAID)

Investigators

  • Principal Investigator: Amy D Klion, M.D., National Institute of Allergy and Infectious Diseases (NIAID)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 11, 2025

Primary Completion (Estimated)

January 30, 2027

Study Completion (Estimated)

January 30, 2027

Study Registration Dates

First Submitted

March 11, 2025

First Submitted That Met QC Criteria

March 11, 2025

First Posted (Actual)

March 12, 2025

Study Record Updates

Last Update Posted (Actual)

September 4, 2026

Last Update Submitted That Met QC Criteria

September 3, 2026

Last Verified

August 10, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 10002302
  • 002302-I

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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