Selective colonization of insoluble substrates by human faecal bacteria

E Carol McWilliam Leitch, Alan W Walker, Sylvia H Duncan, Grietje Holtrop, Harry James Flint

Research output: Contribution to journalArticle

149 Citations (Scopus)

Abstract

Insoluble plant polysaccharides and endogenous mucin are important energy sources for human colonic microorganisms. The object of this study was to determine whether or not specific communities colonize these substrates. Using faecal samples from four individuals as inocula for an anaerobic in vitro continuous flow system, the colonization of wheat bran, high amylose starch and porcine gastric mucin was examined. Recovered substrates were extensively washed and the remaining tightly attached bacterial communities were identified using polymerase chain reaction-amplified 16S rRNA gene sequences and fluorescent in situ hybridization. The substrate had a major influence on the species of attached bacteria detected. Sequences retrieved from bran were dominated by clostridial cluster XIVa bacteria, including uncultured relatives of Clostridium hathewayi, Eubacterium rectale and Roseburia species. Bacteroides species were also detected. The most abundant sequences recovered from starch were related to the cultured species Ruminococcus bromii, Bifidobacterium adolescentis, Bifidobacterium breve and E. rectale. The most commonly recovered sequences from mucin were from Bifidobacterium bifidum and uncultured bacteria related to Ruminococcus lactaris. This study suggests that a specific subset of bacteria is likely to be the primary colonizers of particular insoluble colonic substrates. For a given substrate, however, the primary colonizing species may vary between host individuals.

Original languageEnglish
Pages (from-to)667-679
Number of pages13
JournalEnvironmental Microbiology
Volume9
Issue number3
Early online date6 Dec 2006
DOIs
Publication statusPublished - Mar 2007

Keywords

  • Amylose
  • Bacteria
  • Bacterial Adhesion
  • Colony Count, Microbial
  • DNA, Bacterial
  • DNA, Ribosomal
  • Dietary Fiber
  • Feces
  • Gastric Mucins
  • Genes, rRNA
  • Humans
  • In Situ Hybridization, Fluorescence
  • Molecular Sequence Data
  • Phylogeny
  • Polymerase Chain Reaction
  • RNA, Ribosomal, 16S
  • Solubility
  • Substrate Specificity
  • 16s ribosomal-RNA
  • gradient gel-electrophoresis
  • human gastrointestinal-tract
  • continuous-culture system
  • human colonic bacteria
  • human feces
  • human gut
  • sp nov.
  • plant polysaccharides
  • clostridium-hathewayi

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