Background and Aim: Helicobacter pylori is one of the most common pathogenic bacteria in the human gut, and is also one of the most important factors that cause digestive disorders such as chronic inflammation, gastric ulcers, and even gastric cancer. Since the use of various antibiotics to treat H. pylori infection is associated with the development of resistance in this bacterium, the aim of this study was to determine the anti-H. pylori effects of Lactobacillus acidophilus, L. plantarum, and L. rhamnosus in the stomach tissue of C57BL/6 mice. Materials and Methods: In this experimental study, 70 mice in ten groups were evaluated from July to September 2017 in the microbiology laboratory of the School of Medicine, Alborz University of Medical Sciences, Karaj, Iran. After induction of H. pylori infection in mice with the standard strain of H. pylori (ATCC 43504), the infected mice were treated with drug and Lactobacillus species in different groups. Then, the anti-H. pylori effects of lactobacilli were evaluated by stool antigen test and tissue staining. Results: Based on ELISA results and histological findings, a reduction of inflammation was observed. The group which was only exposed to L. rhamnosus and the one which was exposed to all three strains of Lactobacillus showed the highest antimicrobial effect on H. pylori. Conclusion: According to the results of this study, probiotic bacteria including L. acidophilus, L. plantarum, and L. rhamnosus could be useful in the reduction of H. pylori infection in the mouse model.