Safety and immunogenicity of Helicobacter pylori clinical isolates in healthy volunteers.

INTERVENTION: This study will evaluate the safety and immunogenicity of selected H. pylori clinical strains in healthy human volunteers that have not been previously exposed to H. pylori. The study will include 5 clinical isolates and a placebo group. Subjects will be randomised into 6 groups of 6, totally 36 subjects in total. Each participant will only receive either a single oral dose (30 mls) of one of the five H. pylori strains, or the placebo. The H. pylori inoculum or placebo will be administered 90 days after screening, and eradication therapy commenced 30 days after inoculum or placebo administration. The eradication therapy consists of NEXIUM Hp7 (Esomeprazole 20mg, amoxycillin trihydrate 1000mg, and clarithromycin 500mg); the tablets are taken twice a day for one week. CONDITION: This study will evaluate the safety and immunogenicity of selected Helicobacter Pylori (H.pylori) clinical strains in healthy human volunteers that have not been previously exposed to H. pylori. PRIMARY OUTCOME: To observe the clinical effect of Helicobacter pylori infection. ; ; 1.Live Helicobacter pylori are administered ; to healthy subjects ; a.Symptom diary cards are completed ; b.Infection status is determined at the ; 2‐week gastroscopy ; ; 2.The subject completes the follow‐up ; period ; a. The final endoscopy is completed ; b. Eradication treatment is completed ; by the patient ; c. Follow‐up breath tests confirm ; eradication of Helicobacter pylori ; ; Selected H. pylori strains will be administered to naive (sero‐negative) healthy subjects. Infection status will be determined by histological assessment of gastric tissue (biopsies taken at 0, 2 and 12 weeks after infection), blood profiles, liver function test (LFT), cell counts, pH, acid, and the daily diary and telephone follow‐up for adverse events. SECONDARY OUTCOME: To determine the immunogenicity and metabolites of H. pylori in naive (sero‐negative) healthy subjects ; ; 1. Immunogenicity will be determined by measuring H. pylori specific immunoglobulin responses and serum cytokine responses in the blood at intervals during the study. Urine samples will be assessed for the presence of H. pylori metabolites. INCLUSION CRITERIA: Inclusion Criteria 1. Healthy men and women 2. Aged 18‐70 years inclusive 3. Use their own mobile phone 4. Sero‐negative for H. pylori 5. Asymptomatic with regard to dyspepsia. Mild symptomatic but endoscopy negative gastro‐oesophageal reflux disease is not an exclusion providing the condition does not require the regular use of Proton Pump Inhibitors or H2 blockers (occasional use permitted). However the participants with the following medical conditions will be excluded: a.)Peptic Ulcer Disease b.)History of major gastrointestinal surgery e.g. gastric banding 6. No known allergy to principal medications / antibiotics used to treat H. pylori in this study (esomeprazole, amoxycillin, clarithromycin and tinidazole). No known intolerances or allergy to 2nd and 3rd line medications /antibiotics used to treat H. pylori, including macrolides, tetracycline, fluoroquinolones, furazolidone, colloidal bismuth subcitrate. 7. Liv