Inhibitory effects of Lactobacillus reuteri strain I300 against Helicobacter pylori adhesion, invasion, and inflammatory response in gastric epithelial cells in vitro.

The increasing rate of Helicobacter pylori (H. pylori) antibiotic resistance has attenuated the effectiveness of conventional antibiotic-based treatment regimens. This study was aimed at investigating the in vitro inhibitory effects of Lactobacillus reuteri (L. reuteri) strain I300 against H. pylori. The inhibitory effects of live L. reuteri I300 and its different formulations I300L, I300G, and I300T were examined on H. pylori adhesion and invasion to AGS cells. Auto-aggregation and co-aggregation assays and also scanning electron microscopy were performed, evaluating L. reuteri capacity to auto-aggregate and co-aggregate with H. pylori. RT-qPCR and ELISA were used to investigate the expression, and production level of inflammation-related cytokines TNF-α, IL-8, and IL-10. E-cadherin expression level was also measured, determining L. reuteri potential effect on AGS cells integrity. L. reuteri presented a time-dependent capacity to auto-aggregate and co-aggregate with H. pylori. Live L. reuteri and its formulations significantly reduced H. pylori adhesion and invasion of AGS cells. H. pylori treatment with L. reuteri reduced proinflammatory cytokines TNF-α and IL-8 production while increasing anti-inflammatory cytokine IL-10 production. L. reuteri promoted the epithelial cell-cell contact by upregulating E-cadherin expression. This study indicated L. reuteri I300 as a potential probiotic strain with co-aggregation capacity and inhibitory effects against H. pylori adhesion, invasion, and inflammation.