Evaluation of the Impact of the Probiotic Nissle 1917 on 's Invasion and Intracellular Survival in Human Colonic Cells.

is a leading cause of bacterial food poisoning in humans. Due to the rise in antibiotic-resistant , there exists a need to develop antibiotic-independent interventions to control infections in humans. Here, we evaluated the impact of Nissle 1917 (EcN), a probiotic strain, on invasion and intracellular survival in polarized human colonic cells (HT-29). To further understand how EcN mediates its impact, the expression of 84 genes associated with tight junctions and cell adhesion was profiled in HT-29 cells after treatment with EcN and challenge with . The pre-treatment of polarized HT-29 cells with EcN for 4 h showed a significant effect on 's invasion (∼2 log reduction) of the colonic cells. Furthermore, no intracellular were recovered from EcN pre-treated HT-29 cells at 24 h post-infection. Other probiotic strains tested had no significant impact on invasion and intracellular survival. decreased the expression of genes associated with epithelial cells permeability and barrier function in untreated HT-29 cells. However, EcN positively affected the expression of genes that are involved in enhanced intestinal barrier function, decreased cell permeability, and increased tight junction integrity. The results suggest that EcN impedes invasion and subsequent intracellular survival by affecting HT-29 cells barrier function and tight junction integrity. We conclude that EcN might be a viable alternative for controlling infections.