title: Probiotic Escherichia coli Nissle 1917 inhibits leaky gut by enhancing mucosal integrity.
abstract: BACKGROUND
  Probiotics are proposed to positively modulate the intestinal epithelial barrier formed by intestinal epithelial cells (IECs) and intercellular junctions. Disruption of this border alters paracellular permeability and is a key mechanism for the development of enteric infections and inflammatory bowel diseases (IBDs).
  
  
  RESULTS
  To study the in vivo effect of probiotic Escherichia coli Nissle 1917 (EcN) on the stabilization of the intestinal barrier under healthy conditions, germfree mice were colonized with EcN or K12 E. coli strain MG1655. IECs were isolated and analyzed for gene and protein expression of the tight junction molecules ZO-1 and ZO-2. Then, in order to analyze beneficial effects of EcN under inflammatory conditions, the probiotic was orally administered to BALB/c mice with acute dextran sodium sulfate (DSS) induced colitis. Colonization of gnotobiotic mice with EcN resulted in an up-regulation of ZO-1 in IECs at both mRNA and protein levels. EcN administration to DSS-treated mice reduced the loss of body weight and colon shortening. In addition, infiltration of the colon with leukocytes was ameliorated in EcN inoculated mice. Acute DSS colitis did not result in an anion secretory defect, but abrogated the sodium absorptive function of the mucosa. Additionally, intestinal barrier function was severely affected as evidenced by a strong increase in the mucosal uptake of Evans blue in vivo. Concomitant administration of EcN to DSS treated animals resulted in a significant protection against intestinal barrier dysfunction and IECs isolated from these mice exhibited a more pronounced expression of ZO-1.
  
  
  CONCLUSIONS
  This study convincingly demonstrates that probiotic EcN is able to mediate up-regulation of ZO-1 expression in murine IECs and confer protection from the DSS colitis-associated increase in mucosal permeability to luminal substances.
authors: Department of Mucosal Immunity, Helmholtz Centre for Infection Research, Braunschweig, Germany.
authors: Sya N
authors: SN
authors: Ukena
authors: Anurag
authors: A
authors: Singh
authors: Ulrike
authors: U
authors: Dringenberg
authors: Regina
authors: R
authors: Engelhardt
authors: Ursula
authors: U
authors: Seidler
authors: Wiebke
authors: W
authors: Hansen
authors: André
authors: A
authors: Bleich
authors: Dunja
authors: D
authors: Bruder
authors: Anke
authors: A
authors: Franzke
authors: Gerhard
authors: G
authors: Rogler
authors: Sebastian
authors: S
authors: Suerbaum
authors: Jan
authors: J
authors: Buer
authors: Florian
authors: F
authors: Gunzer
authors: Astrid M
authors: AM
authors: Westendorf
mesh_terms: D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D003092:Colitis / Q000503:physiopathology / Q000628:therapy*; D017931:DNA Primers; D004926:Escherichia coli; D005260:Female; D005455:Fluorescent Antibody Technique; D005856:Germ-Free Life; D007413:Intestinal Mucosa / Q000503:physiopathology*; D051379:Mice; D008807:Mice, Inbred BALB C; D019936:Probiotics
chemical_list: D017931:DNA Primers