title: Purified galactooligosaccharide, derived from a mixture produced by the enzymic activity of Bifidobacterium bifidum, reduces Salmonella enterica serovar Typhimurium adhesion and invasion in vitro and in vivo.
abstract: The prebiotic Bimuno(®) is a mixture containing galactooligosaccharides (GOSs), produced by the galactosyltransferase activity of Bifidobacterium bifidum NCIMB 41171 using lactose as the substrate. Previous in vivo and in vitro studies demonstrating the efficacy of Bimuno(®) in reducing Salmonella enterica serovar Typhimurium (S. Typhimurium) colonization did not ascertain whether or not the protective effects could be attributed to the prebiotic component GOS. Here we wished to test the hypothesis that GOS, derived from Bimuno(®), may confer the direct anti-invasive and protective effects of Bimuno(®). In this study the efficacy of Bimuno(®), a basal solution of Bimuno(®) without GOS [which contained glucose, galactose, lactose, maltodextrin and gum arabic in the same relative proportions (w/w) as they are found in Bimuno(®)] and purified GOS to reduce S. Typhimurium adhesion and invasion was assessed using a series of in vitro and in vivo models. The novel use of three dimensionally cultured HT-29-16E cells to study prebiotics in vitro demonstrated that the presence of ∼ 5 mg Bimuno(®) ml(-1) or ∼ 2.5 mg GOS ml(-1) significantly reduced the invasion of S. Typhimurium (SL1344nal(r)) (P<0.0001). Furthermore, ∼ 2.5 mg GOS ml(-1) significantly reduced the adherence of S. Typhimurium (SL1344nal(r)) (P<0.0001). It was demonstrated that cells produced using this system formed multi-layered aggregates of cells that displayed excellent formation of brush borders and tight junctions. In the murine ligated ileal gut loops, the presence of Bimuno(®) or GOS prevented the adherence or invasion of S. Typhimurium to enterocytes, and thus reduced its associated pathology. This protection appeared to correlate with significant reductions in the neutral and acidic mucins detected in goblet cells, possibly as a consequence of stimulating the cells to secrete the mucin into the lumen. In all assays, Bimuno(®) without GOS conferred no such protection, indicating that the basal solution confers no protective effects against S. Typhimurium. Collectively, the studies presented here clearly indicate that the protective effects conferred by Bimuno(®) can be attributed to GOS.
authors.affiliation: Veterinary Laboratories Agency (VLA), Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: Laura E J
authors.initials: LEJ
authors.lastname: Searle
authors.affiliation: Veterinary Laboratories Agency (VLA), Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: William A
authors.initials: WA
authors.lastname: Cooley
authors.affiliation: Veterinary Laboratories Agency (VLA), Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: Gareth
authors.initials: G
authors.lastname: Jones
authors.affiliation: Veterinary Laboratories Agency (VLA), Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Nunez
authors.affiliation: Veterinary Laboratories Agency (VLA), Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: Bentley
authors.initials: B
authors.lastname: Crudgington
authors.affiliation: Veterinary Laboratories Agency (VLA), Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: Ute
authors.initials: U
authors.lastname: Weyer
authors.affiliation: Faculty of Veterinary Science, University of Liverpool, Leahurst, Chester High Road, Neston, Wirral CH64 7TE, UK.
authors.forename: Alexandra H
authors.initials: AH
authors.lastname: Dugdale
authors.affiliation: Clasado Ltd, 5 Canon Harnett Court, Wolverton Mill, Milton Keynes MK12 5NF, UK.
authors.forename: George
authors.initials: G
authors.lastname: Tzortzis
authors.affiliation: Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Flowers Building, Imperial College London, London SW7 2AZ, UK.
authors.forename: James W
authors.initials: JW
authors.lastname: Collins
authors.affiliation: Veterinary Laboratories Agency (VLA), Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Woodward
authors.affiliation: Microbial Sciences Division, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.|Veterinary Laboratories Agency (VLA), Weybridge, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: Roberto M
authors.initials: RM
authors.lastname: La Ragione
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects*; D001644:Bifidobacterium / Q000201:enzymology*; D005260:Female; D019073:HT29 Cells; D006801:Humans; D051379:Mice; D008855:Microscopy, Electron, Scanning; D009844:Oligosaccharides / Q000494:pharmacology*; D012480:Salmonella Infections / Q000382:microbiology; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000502:physiology*
chemical_list: D009844:Oligosaccharides