Article Text

PDF
GI highlights from the literature
  1. Mairi H McLean, Education editor

Statistics from Altmetric.com

Basic science

Microbially induced expression of GLP-1 can regulate intestinal transit

▸ Plovier H, Lunden GO, Larsson T, et al. Microbial modulation of energy availability in the colon regulates intestinal transit. Cell Host Microbe 2013;14:582–90.

The gut microbiota has coevolved with the host and contributes to host metabolic efficiency through fermentation of dietary substrates and the production of short-chain fatty acids (SCFAs) such as butyrate, acetate and lactate. In humans consuming a Western diet microbially produced SCFAs contribute to approximately 10% of total energy requirements and is much higher than this for people consuming high-fibre diets. SCFAs, act as a primary energy source for colonocytes. They are also proposed to stimulate secretion of the proglucagon (Gcg)-derived incretin hormone GLP-1, which stimulates insulin secretion and inhibits gastric emptying. Wichmann and colleagues investigated how the gut microbiota affected GLP-1 production by comparing germ-free and conventionally raised mice. They showed that in the absence of microbially produced SCFAs there was increased plasma GLP-1, and this GLP-1 derived from the colon had an important role in slowing small bowel transit. Increasing energy availability by re-introducing short-chain or long-chain fatty acids (either through microbial colonisation or dietary fatty acid supplementation) led to reduced colonic Gcg expression. This suggests that there is a local sensing of energy availability that regulates basal GLP-1 secretion according to need. Antibiotic treatment of conventionally raised mice also resulted in reduced SCFA levels and increased Gcg expression and GLP-1 levels. The authors suggest that continuous production of SCFAs by the gut microbiota under normal physiological conditions may play a role in establishing basal GLP-1 levels. They propose that colonic GLP-1 has an important role in slowing intestinal transit in response to insufficient energy availability in the colon. The findings eloquently demonstrate a further example of how the gut microbiota contributes to host physiology and potentially holds the key …

View Full Text

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.