title: Isolation and characterisation of new putative probiotic bacteria from human colonic flora.
abstract: The present study describes a novel bacterial isolate exhibiting high ability to synthesise and secrete butyrate. The novel isolated bacterium was obtained from human faeces and grown in selective liquid intestinal microflora medium containing rumen fluid under microaerobic conditions. Its probiotic properties were demonstrated by the ability of the isolate to survive high acidity and medium containing bile acids and the ability to adhere to colon cancer cells (Caco-2) in vitro. Phylogenetic identity to Enterococcus durans was established using specific primers for 16S rRNA (99% probability). PCR analyses with primers to the bacterial gene encoding butyrate kinase, present in the butyrogenic bacteria Clostridium, showed that this gene is present in E. durans. The in vivo immunoprotective and anti-inflammatory effects of E. durans were assessed in dextran sodium sulfate (DSS)-induced colitis in Balb/c mice. Administration of E. durans ameliorated histological, clinical and biochemical scores directly related to intestinal inflammation whereas the lactic acid bacterium Lactobacillus delbrueckii was ineffective in this regard. Colonic cDNA concentrations of IL-1beta and TNF-alpha were significantly down regulated in DSS-treated E. durans-fed mice but not in control or DSS-treated L. delbrueckii- fed mice. Fluorescent in situ hybridisation analyses of colonic tissue from mice fed E. durans, using a butyrate kinase probe, demonstrated that E. durans significantly adheres to the colonic tissue. The novel isolated bacterium described in the present paper, upon further characterisation, can be developed into a useful probiotic aimed at the treatment of patients suffering from ulcerative colitis.
authors.affiliation: Institute of Biochemistry, Food Science and Nutrition, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem PO Box 12, Rehovot 76100, Israel.
authors.forename: Irit
authors.initials: I
authors.lastname: Raz
authors.forename: Natan
authors.initials: N
authors.lastname: Gollop
authors.forename: Sylvie
authors.initials: S
authors.lastname: Polak-Charcon
authors.forename: Betty
authors.initials: B
authors.lastname: Schwartz
mesh_terms: D001422:Bacterial Adhesion; D002087:Butyrates / Q000378:metabolism; D018938:Caco-2 Cells; D003092:Colitis / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control; D003106:Colon / Q000378:metabolism / Q000382:microbiology*; D015169:Colony Count, Microbial; D016264:Dextran Sulfate; D016983:Enterococcus / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism; D005243:Feces / Q000382:microbiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017404:In Situ Hybridization, Fluorescence; D019936:Probiotics / Q000302:isolation & purification*
chemical_list: D002087:Butyrates; D016264:Dextran Sulfate