Dietary non-digestible carbohydrates promote L-cell differentiation in the proximal colon of rats

Br J Nutr. 2007 Jul;98(1):32-7. doi: 10.1017/S0007114507691648. Epub 2007 Mar 19.

Abstract

One of the challenges in type 2 diabetes treatment is to ensure pancreas functionality with gut peptides such as glucagon-like peptide-1 (GLP-1). We have recently shown that the endogenous GLP-1 production is promoted by dietary non-digestible carbohydrates (oligofructose), the higher GLP-1 secretion could participate in the control of obesity and associated disorders. This experimental study was designed to highlight the mechanisms of endogenous increase of GLP-1 following non-digestible carbohydrate feeding. Male Wistar rats were fed a standard diet (70.4 g/100 g total carbohydrates; controls) or the same diet supplemented with oligofructose (10 g/100 g diet) for 4 weeks. GLP-1-producing L-cells of the colon were quantified by immunohistochemistry. GLP-1 was quantified by ELISA, and proglucagon, neurogenin 3 and NeuroD mRNA were measured in the colon by quantitative RT-PCR. The number of GLP-1-expressing cells was doubled in the proximal colon of oligofructose-treated rats, a phenomenon correlated with the increase in proglucagon mRNA and peptide content in the tissue. Moreover, oligofructose increased the number of enteroendocrine L-cells in the proximal colon by a mechanism involving up-regulation of two differentiation factors: neurogenin 3 and NeuroD. It is the first demonstration that nutrients fermented in the gut may promote L-cell differentiation in the proximal colon, a phenomenon contributing to a higher endogenous GLP-1 production. These results suggest a new mechanism by which dietary fibres may lower food intake and fat mass development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipose Tissue / metabolism
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / analysis
  • Body Weight / physiology
  • Cell Differentiation / physiology
  • Colon / cytology*
  • Colon / metabolism
  • Dietary Carbohydrates / administration & dosage*
  • Dietary Carbohydrates / metabolism
  • Eating / physiology
  • Enteroendocrine Cells / metabolism
  • Enteroendocrine Cells / physiology*
  • Fermentation / physiology
  • Glucagon-Like Peptide 1 / biosynthesis*
  • Male
  • Nerve Tissue Proteins / analysis
  • Oligosaccharides / administration & dosage*
  • Oligosaccharides / metabolism
  • Rats
  • Rats, Wistar

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Dietary Carbohydrates
  • Nerve Tissue Proteins
  • Neurog3 protein, rat
  • Oligosaccharides
  • oligofructose
  • NeuroD protein
  • Glucagon-Like Peptide 1