摘要:Background Previous studies suggested that probiotics intervention may be one of the methods for preventing and/or treating gastric ulcer. Objective The aim of the study was to compare the preventive effects of a spaceflight mutant Lactobacillus reuteri F-9-35 and its wild type on ethanol-induced gastric injury in rats. Design Forty rats were randomly allocated into five groups: a normal group (NOR), ethanol group (EtOH), skim milk group (MILK), L. reuteri F-9-35 group (F935) and wild-type group (WT). The NOR and EtOH groups received 1 ml of distilled water by daily gavage for 14 days. The MILK group received 1 ml of skim milk alone, while the F935 and WT groups were administered 1 ml of skim milk containing the mutant and wild type (1 × 10 10 colony-forming unit/ml) by daily gavage for 14 days, respectively. Acute gastric injury was induced by absolute alcohol 1 h after the final administration of different treatments, except for the NOR group. Results Pretreatment with L. reuteri F-9-35, but not milk alone or milk with the L. reuteri wild type, showed significant reduction of ethanol-induced gastric injury, as evidenced by lowering of ulcer index, ulcer area (%), and histological lesion. F-9-35 decreased the levels of lipid peroxidation and myeloperoxidase and increased mucus, glutathione, and nitric oxide levels in gastric tissue. Moreover, F-9-35 inhibited the expression of proinflammatory genes including gastric tumor necrosis factor-α, interleukin-1β, and cyclooxygenase-2 and decreased the activity of nuclear factor kappa B (NF-κB). Conclusion These findings indicated that L. reuteri F-9-35 pretreatment can attenuate ethanol-induced gastric injury in rats by inhibiting oxidative stress and inflammatory response. Together, L. reuteri F-9-35 has potential preventive efficacy on gastric ulcer.