L-Glutamate supplementation improves small intestinal architecture and enhances the expressions of jejunal mucosa amino acid receptors and transporters in weaning piglets

PLoS One. 2014 Nov 4;9(11):e111950. doi: 10.1371/journal.pone.0111950. eCollection 2014.


L-Glutamate is a major oxidative fuel for the small intestine. However, few studies have demonstrated the effect of L-glutamate on the intestinal architecture and signaling of amino acids in the small intestine. The aim of this study was to investigate the effects of dietary L-glutamate supplementation on the intestinal architecture and expressions of jejunal mucosa amino acid receptors and transporters in weaning piglets. A total of 120 weaning piglets aged 35 ± 1 days with an average body weight at 8.91 ± 0.45 kg were randomly allocated to two treatments with six replicates of ten piglets each, fed with diets containing 1.21% alanine, or 2% L-glutamate. L-Glutamate supplementation increased the activity of glutamate oxaloacetate transaminase (GOT) in the jejunal mucosa. Also, the mRNA expression level of jejunal mucosa glutamine synthetase (GS) was increased by L-glutamate supplementation. The height of villi in duodenal and jejunal segments, and the relative mRNA expression of occludin and zonula occludens protein-1 (ZO-1) in jejunal mucosa were increased by dietary L-glutamate supplementation. L-Glutamate supplementation increased plasma concentrations of glutamate, arginine, histidine, isoleucine, leucine, methionine, phenylalanine and threonine. L-Glutamate supplementation also increased the relative mRNA expression of the jejunal mucosa Ca(2+)-sensing receptor (CaR), metabotropic glutamate receptor 1 (mGluR1) and metabotropic glutamate receptor 4 (mGluR4), and neutral amino acid transporter B(0)-like (SLC1A5) in the jejunal mucosa. These findings suggest that dietary addition of 2% L-glutamate improves the intestinal integrity and influences the expression of amino acid receptors and transporters in the jejunum of weaning, which is beneficial for the improvement of jejunal nutrients for digestion and absorption.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport Systems / metabolism*
  • Amino Acids / blood
  • Animals
  • Aspartate Aminotransferases / metabolism
  • Claudin-1 / genetics
  • Claudin-1 / metabolism
  • Dietary Supplements*
  • Gene Expression
  • Glutamic Acid / administration & dosage*
  • Intestinal Mucosa / cytology
  • Intestinal Mucosa / metabolism*
  • Jejunum / cytology
  • Jejunum / metabolism*
  • Male
  • Occludin / genetics
  • Occludin / metabolism
  • Sus scrofa
  • Weaning
  • Zonula Occludens-1 Protein / genetics
  • Zonula Occludens-1 Protein / metabolism


  • Amino Acid Transport Systems
  • Amino Acids
  • Claudin-1
  • Occludin
  • Zonula Occludens-1 Protein
  • Glutamic Acid
  • Aspartate Aminotransferases

Grants and funding

The present study was supported by National Key Basic Research Program of China (no. 2013CB127306). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.