Lactobacillus acidophilus Attenuates Salmonella-Induced Stress of Epithelial Cells by Modulating Tight-Junction Genes and Cytokine Responses

Abstract

Scope: Salmonellosis is a prevalent food-borne illness that causes diarrhea in over 130 million humans yearly and can lead to death. There is an urgent need to find alternatives to antibiotics as many salmonellae are now multidrug resistant. As such, specific beneficial bacteria and dietary fibers can be an alternative as they may prevent Salmonella Typhimurium (STM) infection and spreading by strengthening intestinal barrier function.Methods and Results: We tested whether immune active long-chain inulin-type fructans and/or L. acidophilus W37, L. brevis W63, and L. casei W56 can strengthen barrier integrity of intestinal Caco-2 cells in the presence and absence of a STM. Effects of the ingredients on intestinal barrier function were first evaluated by quantifying trans-epithelial electric resistance (TEER) and regulation of gene expression by microarray. Only L. acidophilus had effects on TEER and modulated a group of 26 genes related to tight-junctions. Inulin-type fructans, L. brevis W63 and L. casei W56 regulated other genes, unrelated to tight-junctions. L. acidophilus also had unique effects on a group of six genes regulating epithelial phenotype toward follicle-associated epithelium. L. acidophilus W37 was therefore selected for a challenge with STM and prevented STM-induced barrier disruption and decreased secretion of IL-8.Conclusion: L. acidophilus W37 increases TEER and can protect against STM induced disruption of gut epithelial cells integrity in vitro. Our results suggest that selection of specific bacterial strains for enforcing barrier function may be a promising strategy to reduce or prevent STM infections.

Antidepressive Mechanisms of Probiotics and Their Therapeutic Potential

“…However, the mood elevation could be due to recovery of gastrointestinal symptoms rather than effect of probiotics solely. Both in vitro and in vivo models showed that L. acidophilus protects the intestinal barrier integrity by preventing pathogen adherence and release of proinflammatory cytokines (Chen et al, 2009;Justino et al, 2015;Alamdary et al, 2018;Lepine et al, 2018;Najarian et al, 2019). Taken together, B. bifidum and L. acidophilus potentially exhibit antidepressive effect and their direct influence on depression warrants further investigation.…”

Oral Administration of a Select Mixture of Lactobacillus and Bacillus Alleviates Inflammation and Maintains Mucosal Barrier Integrity in the Ileum of Pigs Challenged with Salmonella Infantis

“…As a crucial component of the epithelial barrier, they are often targeted by pathogenic bacteria, aiding infection and the development of disease [14]. L. acidophilus attenuated Salmonella -induced stress of epithelial cells by modulating TJs genes [15]. B. subtilis significantly enhanced intestinal barrier integrity by up-regulating tight junction protein expression [16].…”

Effect of fermented milk from Lactococcus lactis ssp. cremoris strain JFR1 on Salmonella invasion of intestinal epithelial cells

“…A similar response was observed by Wagar et al (2009) in which a milk blend fermented by S. thermophilus ST5 and Bifidobacterium longum R0175 significantly reduced the levels of IL-8 produced compared with an acidified milk blend treatment. After stimulation by Salmonella Typhimurium, L. acidophilus W37-treated epithelial cells also displayed decreased amounts of IL-8 (Lépine et al, 2018). Additionally, the immunomodulatory effect of Lactococcus lactis NCDO 2118 demonstrated reduced secretion of IL-8 in vitro (Luerce et al, 2014).…”

“…Interleukin-8 is a proinflammatory cytokine produced by a variety of cell types, including intestinal epithelial cells (Eckmann et al, 1993;Imaoka et al, 2008). There is considerable evidence reporting that LAB and their fermented milks display an overall modulating effect in in vitro studies, specifically in the presence of pathogens, which stimulate inflammatory responses (Zeinhom et al, 2012;Zagato et al, 2014;Chen et al, 2016;Acurcio et al, 2017;Lépine et al, 2018). Although similar to this study, others have reported considerably less production of IL-8 by Caco-2 cells compared with other cell types, including HT-29 and its subsets (Eckmann et al, 1993;Zhang et al, 2005;Ren et al, 2013).…”