Comparison of Lactobacillus rhamnosus GG and luxS mutant on gut barrier function of mice challenged with Escherichia coli

Quorum sensing (QS) is an essential pathway for bacterial communication through autoinducers (AIs). The luxS gene involved in QS has been proven to regulate different behavior of Lactobacillus rhamnosus GG (LGG), whereas it is unclear whether the AI-2/LuxS system have beneficial effects the host by regulating LGG. Our aim was to investigate whether luxS mutation affects the ability of LGG to maintain intestinal microbiota homeostasis, intestinal barrier integrity and inflammatory immune responses in mice infected with Escherichia coli ( E. coli ). This study showed that both wild-type (WT) and luxS mutant (ΔluxS) of LGG can alleviate changes in the microbiota caused by E. coli by down-regulating the relative abundance of Parasturtella . Supplementation with WT and ΔluxS increased the CD4 + /CD8 + ratio in spleen, improved goblet cell numbers and enhanced Muc 2 secretion. Moreover, WT and ΔluxS decreases proinflammatory mediator levels by inhibiting MAPK and NF-κB signal transduction. • Both WT and ΔluxS restored gut microbiota and barrier function challenged by E. coli. • WT and ΔluxS reduce pro-inflammatory mediators by inhibiting MAPK and NF-κB signal transduction. • The ΔluxS did not affect the prebiotic effects of LGG in a conventional mouse model.