DIETARY FACTORS INFLUENCE THE RECOVERY RATES OF HELICOBACTER-PYLORI IN A BALB CA MOUSE MODEL/

The aim of this study was to assess the ability of different mouse die ts to sustain an H. pylori infection in BALB/cA mice. Four commerciall y available mouse diets were compared. Experiment 1: Mice were fed the four diets for seven days before infection, infected three times at t wo-day intervals with 0.1 mi of 10(9) colony-forming units/ml H.pylori cells. H. pylori strains (n = 4) were cultured on GAB-Camp agar for 2 days, harvested and suspended in PBS. All animals were sacrificed at 2 and 4 weeks post inoculation. Experiment 2: Mice infected for 8 week s were fed RM2, changed to the different diets for 10 days and sacrifi ced. Stomachs were collected, cultured on GAB-Camp agar to estimate H. pylori growth and stomach biopsies were analyzed by PCR. There were s ignificant differences between diets in their ability to sustain growt h of H. pylori. The range was from a few hundred colonies to no growth at all on the GAB-Camp agar. PCR signals showed good correlation with the culture results. All H. pylori-infected mice gave a significantly higher inflammation score compared to non-infected mice. The diet RM2 , having the highest number of culturable H. pylori in the mouse stoma ch, also showed the highest inflammation. These results suggest that t he dietary factors affect the amounts of H. pylori in an infection of BALB/cA mice.