Understanding the effects of diet on bacterial metabolism in the large intestine

Research output: Contribution to journalLiterature review

420 Citations (Scopus)

Abstract

Recent analyses of ribosomal RNA sequence diversity have demonstrated the extent of bacterial diversity in the human colon, and have provided new tools for monitoring changes in the composition of the gut microbial community. There is now an excellent opportunity to correlate ecological niches and metabolic activities with particular phylogenetic groups among the microbiota of the human gut. Bacteria that associate closely with particulate material and surfaces in the gut include specialized primary degraders of insoluble substrates, including resistant starch, plant structural polysaccharides and mucin. Butyrate-producing bacteria found in human faeces belong mainly to the clostridial clusters IV and XIVa. In vitro and in vivo evidence indicates that a group related to Roseburia and Eubacterium rectale plays a major role in mediating the butyrogenic effect of fermentable dietary carbohydrates. Additional cluster XIVa species can convert lactate to butyrate, while some members of the clostridial cluster IX convert lactate to propionate. The metabolic outputs of the gut microbial community depend not only on available substrate, but also on the gut environment, with pH playing a major role. Better understanding of the colonic microbial ecosystem will help to explain and predict the effects of dietary additives, including nondigestible carbohydrates, probiotics and prebiotics.

Original languageEnglish
Pages (from-to)1197-1208
Number of pages12
JournalJournal of Applied Microbiology
Volume102
Issue number5
Early online date10 Apr 2007
DOIs
Publication statusPublished - May 2007

Keywords

  • anaerobe
  • butyrate
  • dietary
  • carbohydrate
  • gut bacteria
  • prebiotics
  • starch
  • butyrate-producing bacteria
  • human colonic bacteria
  • in-vitro fermentation
  • chain fatty-acids
  • human gut
  • bacteroides-thetaiotaomicron
  • beta-fructofuranosidase
  • resistant starch
  • human feces
  • fructo-oligosaccharides

Cite this