We aimed to assess the efficacy of Lactobacillus acidophilus and Lactobacillus rhamnosus in the reduction of bacterial load of H. pylori and in the modification of gut microbiotia in this double blind, placebo controlled, randomized trial.

Subjects: Adult subjects aged 20 or greater with moderate to high bacterial load of H. pylori defined as a DOB value greater than 10 will be eligible to this trial. We will screen 150 subjects and it is estimated that 40 H. pylori infected subjects will be eligible. Eligible subjects will be randomized to receive probiotic (Lactobacillus acidophilus and Lactobacillus rhamnosus) or placebo, one pack twice daily, for 28 days. The primary outcome was the reduction in H. pylori load of greater than 20% than baseline. The secondary outcome was the impact of the probiotic on the gut microbiota and the adverse effects.

Inclusion Criteria:

• Adult subjects aged 20 or greater with moderate to high bacterial load of H. pylori defined as a DOB value greater than 10 will be eligible to this trial

Exclusion Criteria:

• history of gastrectomy and colectomy
• severe underlying illness, such as malignancy, ESRD, liver failure, etc
• allergy to probiotics
• symptomatic patients who need PPI, antibiotics, or other probiotics
• pregnancy and lactating women
• unable to cooperate with the protocol