Background: Gastric ulcer treatment with chemical drugs is associated with a multitude of side effect. One of the most important groups of probiotics is lactic acid bacteria. The aim of this study was to investigate the healing effects of Lactobacillus pentosus on gastric ulcer induced by acetic acid.

Materials and Methods: In this experimental study, 45 male Wistar rats were divided into experimental, control 1, and control 2 groups. After one day of fasting, the rats were operated and gastric ulcer was induced by acetic acid. One day after surgery, the groups were treated with the 1010 cfu/day bacteria, dissolved in one ml of milk sterilizer, 1 ml of milk sterilizer, and 1 ml of normal saline, respectively, via gavage. On days 1, 4, 7, 10, and 14 after the induction of gastric ulcer, the animals were killed and the wound size (mm2) and the effect of the bacteria on the healing of wounds were measured for each rat.

Results: The treatment with Lactobacillus pentosus strains significantly decreased wound size in the experimental group compared with control groups. Significant increases in the number of neutrophils, macrophages, fibroblasts, significant decreases in the number of neutrophils, macrophages, and increased numbers of fibroblasts were observed in the experimental group compared to the control groups. Also, significant reductions in the number of neutrophils, macrophages, and fibroblasts were seen in the experimental group compared with the other two groups.

Conclusion: Lactobacillus pentosus has healing effects on gastric ulcer induced by acetic acid.