Peptic ulcer disease (PUD) is still a global public health problem. Development of novel therapies became necessary to overcome the limitations of traditional therapies. In this study we intend to treat experimentally induced peptic ulcer by using a new probiotic bacterial strain.Lactobacillus reuteri NA1 was isolated from peptic ulcer human-biopsy on MRS medium, molecularly identified, and registered in GenBank with accession number MH714546. This study was conducted on 2 experiments, the first experiment included 48 rats divided into 4 groups. Saline group, negative control group (saline); H.p. 1 group, H. pylori -ve stool administrated group; H.p. 2 group, H. pylori +ve stool administrated group; H.p. 3 group, H. pylori induced ulcer and treated with L. reuteri NA1. The second experiment included 36 rats divided into 3 groups. Saline group, negative control group (saline); As. 1 group, aspirin induced ulcer group; As. 2 group, aspirin induced ulcer and treated with L. reuteri NA1. Histopathological investigations showed a significant recovery of the experimentally induced gastric ulcers by both H. pylori and Aspirin after 6 weeks of the treatment with L. reuteri NA1. Complete healing of gastric mucosa was observed after 12 weeks of daily administration of L. reuteri NA1. L. reuteri NA1 has shown a promising solution for treatment of peptic ulcer in H. pylori- antibiotic resistance patients, and aspirin users.