Probiotics prevent bacterial translocation and improve intestinal barrier function in rats following chronic psychological stress

Abstract

Background and aim: Chronic psychological stress, including water avoidance stress (WAS), induces intestinal mucosal barrier dysfunction and impairs mucosal defences against luminal bacteria. The aim of this study was to determine the ability of a defined probiotic regimen to prevent WAS induced intestinal pathophysiology. Methods: Male rats were subjected to either WAS or sham stress for one hour per day for 10 consecutive days. Additional animals received seven days of Lactobacillus helveticus and L rhamnosus in the drinking water prior to stress and remained on these probiotics for the duration of the study. Rats were then sacrificed, intestinal segments assessed in Ussing chambers, and mesenteric lymph nodes cultured to determine bacterial translocation. Results: All animals remained healthy for the duration of the study. Chronic WAS induced excess ion secretion (elevated baseline short circuit current) and barrier dysfunction (increased conductance) in both the ileum and colon, associated with increased bacterial adhesion and penetration into surface epithelial cells. Approximately 70% of rats subjected to WAS had bacterial translocation to mesenteric lymph nodes while there was no bacterial translocation in controls. Probiotic pretreatment alone had no effect on intestinal barrier function. However, WAS induced increased ileal short circuit current was reduced with probiotics whereas there was no impact on altered conductance. Pretreatment of animals with probiotics also completely abrogated WAS induced bacterial adhesion and prevented translocation of bacteria to mesenteric lymph nodes. Conclusion: These findings indicate that probiotics can prevent chronic stress induced intestinal abnormalities and, thereby, exert beneficial effects in the intestinal tract.

Oral Administration of Heat-KilledLactobacillus plantarumStrain b240 Protected Mice againstSalmonella entericaSerovar Typhimurium

“…Pathological bacterial translocation as a marker of impaired barrier function can also be effectively reduced by probiotic therapy. [27][28][29][30] In conclusion, oral administration of heat-killed b240 was found to reduce S. Typhimurium infection effectively through inhibition of S. Typhimurium adhesion and invasion of intestinal epithelial cells, which normally leads to systemic infection associated with multiple organ failure. Heat-killed b240 thus appears to play a valuable role in preventing the lethality of S. Typhimurium infection in mice.…”

Probiotic Fermented Milk Containing Dietary Fiber Has Additive Effects in IBS with Constipation Compared to Plain Probiotic Fer-mented Milk

“…24,25 Others have anti-inflammatory effects 26 or enhance the mucosal defense against luminal bacteria by preventing bacterial adherence to the epithelial cell surface, eliminating bacterial translocation and decreasing the increased intestinal permeability. 27 Rousseaux et al 22 reported that Lactobacillus NCFM induced, through the NF-κB pathway, MOR1 and CB2 expression, which contributed to the modulation and restoration of the normal perception of visceral pain. Sinn et al 9 demonstrated reduction of abdominal pain or discomfort among patients receiving a daily dose of 2×10 9 cfu of L. acidophilus-SDC 2012,2013 over four weeks.…”

Regulation of human epithelial tight junction proteins by Lactobacillus plantarum in vivo and protective effects on the epithelial barrier

“…Some probiotic studies in humans have reported a decrease in intestinal permeability (36,38), whereas others have been negative or inconclusive (11,24), suggesting that this activity may depend on the probiotic strain and species as well as the target population and its resilience capacity of the intestinal mucosa. Evidence for probiotic effects on barrier function has also been demonstrated in rat models of chronic stress, hemorrhagic shock, and sepsis although the mechanisms have not been elucidated (32,47). Recently, the probiotic Escherichia coli (E. coli) Nissle 1917 was shown to inhibit a leaky gut by upregulation of ZO-1 expression in murine intestinal epithelial cells and to confer protection from dextran sodium sulfate (DSS)-induced colitis (41,48).…”