Lactobacillus rhamnosus JB3 inhibits Helicobacter pylori infection through multiple molecular actions

Eradication of Helicobacter pylori infection is the most direct and effective way for preventing gastric cancer. Lactic acid bacteria are considered as alternative therapeutic agents against H. pylori infection.

Effects of Lactobacillus rhamnosus JB3 (LR-JB3) on the virulence gene expression of H. pylori and infection-induced cellular responses of AGS cells were investigated by co-cultivating infected AGS cells with different multiplicity of infections (MOIs) of LR-JB3.

LR-JB3, specifically at a MOI of 25, suppressed the association ability of H. pylori and its induced IL-8 levels, as well as the mRNA levels of vacA, sabA, and fucT of H. pylori, infection-induced Lewis (Le)^x antigen and Toll-like receptor 4 (TLR4) expressions in AGS cells. However, the apoptosis mediated by infection was inhibited by LR-JB3 in a dose-dependent manner. In addition, autoinducer (AI)-2 was observed to have increased the association ability and fucT expression of H. pylori, and Le^x antigen and TLR4 expression of AGS cells. Interestingly, an unknown bioactive cue was hypothesized to have been secreted from LR-JB3 at a MOI of 25 to act as an antagonist of AI-2.

LR-JB3 possesses various means to interfere with H. pylori pathogenesis and infection-induced cellular responses of AGS cells to fight against infection.