Clinical Experiment of Helicobacter Pylori Transmission

NCT ID: NCT00550368

Last Updated: 2016-12-06

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 45 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2005-08-31
• Study Completion Date: 2009-04-30

Brief Summary

The study proposes to test whether chronic infection with Helicobacter pylori protects individuals from symptomatic infection with enteropathogenic E. coli. The study will also evaluate the effect of gastric acidity in this relationship.

Detailed Description

Because H. pylori is an enteric infection, its prevalence may be linked to exposure to other enteric pathogens. Results of observational studies on the association between H. pylori and gastroenteritis, however, have been conflicting. Some have shown increased incidence of diarrhea in children with H. pylori infection, with one study attributing 11% of diarrhea cases to H. pylori. Other studies found no association, and still others found a protective effect of H. pylori against gastroenteritis. Dissecting out confounding from true physiological associations can be difficult in observational studies. To better elucidate the association between H. pylori and gastroenteritis, we performed a direct challenge experiment with a well-characterized gastrointestinal pathogen, enteropathogenic Escherichia coli (EPEC). EPEC is a leading cause of infantile gastroenteritis in the world and has a long history of safe use in human experiments. It is also acid sensitive: in our laboratory less than 0.001% of inoculated EPEC organisms survived at pH 2.5. Our goal was to test the hypothesis that chronic infection with H. pylori increases the risk of diarrheal illness after direct challenge with EPEC.

Conditions

Infection; Achlorhydria

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Helicobacter pylori negative

Persons who tested negative for H. pylori by both serology and Urea breath test. All participants will receive the Biological intervention: Enteropathogenic E. coli.

Group Type: EXPERIMENTAL

Biological intervention: Enteropathogenic E. coli

Intervention Type: BIOLOGICAL

5x10\^8 or 1x10\^9 organisms of EPEC were administered to all participants.

Helicobacter pylori positive

Persons who tested positive for H. pylori by both serology and Urea breath test. All participants will receive the Biological intervention: Enteropathogenic E. coli.

Group Type: EXPERIMENTAL

Biological intervention: Enteropathogenic E. coli

Intervention Type: BIOLOGICAL

5x10\^8 or 1x10\^9 organisms of EPEC were administered to all participants.

Interventions

Biological intervention: Enteropathogenic E. coli

5x10\^8 or 1x10\^9 organisms of EPEC were administered to all participants.

Intervention Type: BIOLOGICAL

Eligibility Criteria

Inclusion Criteria

Inclusion Criteria:Healthy Exclusion Criteria:prior gastrointestinal disease prior treatment of H. pylori infection immune suppression or deficiency history of cancer, diabetes, or other co-morbidity

• Minimum Eligible Age: 35 Years
• Maximum Eligible Age: 59 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Stanford University

OTHER

Sponsor Role: lead

Responsible Party

Julie Parsonnet

Principle Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Julie Parsonnet

Role: PRINCIPAL_INVESTIGATOR

Stanford University

Locations

Stanford University School of Medicine

Stanford, California, United States

Countries

United States

Other Identifiers

688

Identifier Type: -

Identifier Source: org_study_id

NCT00549224

Identifier Type: -

Identifier Source: nct_alias