Effect of probiotics on enterocyte bacterial translocation in vitro

Abstract

Enteral probiotics such as Lactobacillus casei GG (LGG) have been used in the treatment of a variety of intestinal disorders in infants and children, including diarrhea, malabsorption, and Clostridium difficile colitis. We have previously demonstrated that the probiotic bacterium LGG has an inhibitory effect on bacterial translocation (BT) in a neonatal rabbit model. However, this in-vivo model is limited for investigating the cellular and molecular mechanisms responsible for probiotic inhibition of BT. The purpose of this study was to determine the efficacy of LGG in reducing the rate of Escherichia coli C25 (E. coli C25) translocation using an in-vitro enterocyte cell-culture model. Human colonic carcinoma (Caco-2) enterocytes were seeded in porous filters in the apical chamber of a two-chamber cell-culture system and grown for 14 days to confluence. The monolayers were incubated at 37 degrees C with LGG for 180 min. Non-adherent LGG was washed away prior to a 120-min incubation period with 10(5) CFU E. coli C25. E. coli that had translocated across the enterocyte monolayer were quantified by growing basal-chamber media samples on gram-negative bacteria-specific MacConkey's agar. In order to determine monolayer integrity, transepithelial electrical resistance (TEER) was measured across Caco-2 cells treated with LGG and E. coli. Statistical analysis was by ANOVA with P < 0.05 considered significant. LGG inhibited E. coli translocation at all LGG concentrations tested. The TEER ratio was not significantly altered by addition of LGG or E. coli (0.9 +/- 0.03 vs 0.8 +/- 0.05). These results demonstrate that the probiotic bacterium LGG inhibits BT of E. coli C25 in a dose-dependent manner in an in-vitro cell-culture model. This model should be valuable in investigating the cellular and molecular mechanisms involved in the inhibition of pathological enteral bacteria by probiotic agents.

Using a mathematical model to analyze the role of probiotics and inflammation in necrotizing enterocolitis

“…Mattar et al [33] showed that the presence of probiotics in the intestinal lumen generally leads to a decrease in the level of pathogen in the lumen. Our results agree with this finding, assuming a 1 wa 2 .…”

Saccharomyces cerevisiae como probiótico para alevinos de tilápia-do-nilo submetidos a desafio sanitário

“…Probióticos podem ser definidos como microrganismos vivos suplementados aos alimentos e que afetam beneficamente o hospedeiro pela melhora em seu balanço intestinal (Fuller, 1989) e na prevenção de doenças (Mattar et al, 2001). Esses microrganismos têm algum efeito benéfico nos microrganismos presentes no ambiente aquático (Verschuere et al, 2000a).…”

Lactobacillus supplementation for diarrhoea related to chemotherapy of colorectal cancer: a randomised study

“…Some placebocontrolled studies also suggest that probiotics are of benefit in the treatment of antibiotics-associated diarrhoea and in the prevention of nosocomial diarrhoea in infants (Szajewska et al, 2001;Cremonini et al, 2002). The putative mechanisms of L. rhamnosus GG action may include stimulation of the cell proliferation rate of bowel epithelial cells, enhanced secretion of protective mucins leading to reduced adherence of enteropathogenic bacteria to the bowel wall, inhibition of bacterial translocation into the tissues, and stimulation of local and systemic immune response to pathogens (Mattar et al, 2001;Banasaz et al, 2002;Khaled et al, 2003;Mack et al, 2003;Vaarala, 2003). Partially hydrolysed guar gum fibre may also reduce duration of diarrhoea (Homann et al, 1994;Alam et al, 2000) and prolong the colonic transit time (Meier et al, 1993).…”