Butyrate production from oligofructose fermentation by the human faecal flora: what is the contribution of extracellular acetate and lactate?

• Published in: British journal of nutrition Vol. 96; no. 3; pp. 570 - 577
• Main Authors: Morrison, Douglas J., Mackay, William G., Edwards, Christine A., Preston, Tom, Dodson, Brian, Weaver, Lawrence T.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.09.2006
• Subjects: Acetates - metabolism; acetic acid; Adult; Bacteria; Biological and medical sciences; Butyrate; Butyrates - metabolism; butyric acid; butyrogenic prebiotics; Carbohydrates; Carbon Isotopes; Conversion; extracellular space; Fatty Acids, Volatile - metabolism; feces; Feces - microbiology; Feeding. Feeding behavior; Female; Females; Fermentation; Fermentation - physiology; fructose; Fundamental and applied biological sciences. Psychology; Glucose; Glucose - metabolism; Humans; in vitro studies; intestinal microorganisms; Isotopes; lactic acid; Lactic Acid - metabolism; Large intestine; Male; Medical research; Metabolism; Middle Aged; Oligofructose; oligosaccharides; Oligosaccharides - metabolism; Prebiotics; Short-chain fatty acids; Stable isotopes; Vertebrates: anatomy and physiology, studies on body, several organs or systems; United Kingdom > UK; Short-chain fatty acids; Fermentation; Stable isotopes; Oligofructose; Butyrate; Human; Short chain; Lipids; Acetate; Fatty acids; Extracellular; Lactates; Vertebrata; Mammalia; Flora; Short-chain fatty acids: Butyrate: Stable isotopes: Oligofructose: Fermentation; Feces; Isotopes
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1079/BJN20061853

Butyrate is an important substrate for maintenance of colonic health and oligofructose fermentation by human faecal bacteria can increase butyrate production in vitro. However, oligofructose appears to be fermented by mainly acetate and lactate-producing bacteria rather than butyrate-producing bacteria. Isotope labelling studies using [U-13C6]glucose were used to show that 13C2 and 13C4 were the major labelled butyrate species produced from glucose fermentation, via [13C2]acetate–acetyl CoA as intermediate. Bacterial interconversion reactions were quantified and acetate conversion to butyrate and lactate conversion to acetate, propionate and butyrate were observed. Addition of oligofructose to faecal batch cultures significantly increased butyrate production. Of the newly synthesised butyrate from oligofructose fermentation, 80% was derived from interconversion of extracellular acetate and lactate, with acetate being quantitatively more significant. Carbohydrates, such as oligofructose, have prebiotic properties. In addition, oligofructose selectively stimulates the bacterial conversion of acetate and lactate to butyrate. Carbohydrates with similar properties represent a refinement of the prebiotic definition, termed butyrogenic prebiotics, because of their additional functionality.