Clinical Experiment of Helicobacter Pylori Transmission
Clinical Experiment of Helicobacter Pylori Transmission
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.
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.
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