Microbial modulation of energy availability in the colon regulates intestinal transit

Cell Host Microbe. 2013 Nov 13;14(5):582-90. doi: 10.1016/j.chom.2013.09.012.


Gut microbiota contribute to host metabolic efficiency by increasing energy availability through the fermentation of dietary fiber and production of short-chain fatty acids (SCFAs) in the colon. SCFAs are proposed to stimulate secretion of the proglucagon (Gcg)-derived incretin hormone GLP-1, which stimulates insulin secretion (incretin response) and inhibits gastric emptying. We find that germ-free (GF) and antibiotic-treated mice, which have severely reduced SCFA levels, have increased basal GLP-1 levels in the plasma and increased Gcg expression in the colon. Increasing energy supply, either through colonization with polysaccharide-fermenting bacteria or through diet, suppressed colonic Gcg expression in GF mice. Increased GLP-1 levels in GF mice did not improve the incretin response but instead slowed intestinal transit. Thus, microbiota regulate the basal levels of GLP-1, and increasing these levels may be an adaptive response to insufficient energy availability in the colon that slows intestinal transit and allows for greater nutrient absorption.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacteria / metabolism*
  • Carbohydrate Metabolism
  • Colon / microbiology*
  • Dietary Fiber / metabolism*
  • Fatty Acids, Volatile / metabolism
  • Gastrointestinal Transit*
  • Germ-Free Life
  • Glucagon-Like Peptide 1 / blood
  • Mice
  • Proglucagon / metabolism


  • Dietary Fiber
  • Fatty Acids, Volatile
  • Proglucagon
  • Glucagon-Like Peptide 1