L-Theanine Administration Modulates the Absorption of Dietary Nutrients and Expression of Transporters and Receptors in the Intestinal Mucosa of Rats

Biomed Res Int. 2017:2017:9747256. doi: 10.1155/2017/9747256. Epub 2017 Jul 24.

Abstract

L-theanine has various advantageous functions for human health; whether or not it could mediate the nutrients absorption is unknown yet. The effects of L-theanine on intestinal nutrients absorption were investigated using rats ingesting L-theanine solution (0, 50, 200, and 400 mg/kg body weight) per day for two weeks. The decline of insulin secretion and glucose concentration in the serum was observed by L-theanine. Urea and high-density lipoprotein were also reduced by 50 mg/kg L-theanine. Jejunal and ileac basic amino acids transporters SLC7a1 and SLC7a9, neutral SLC1a5 and SLC16a10, and acidic SLC1a1 expression were upregulated. The expression of intestinal SGLT3 and GLUT5 responsible for carbohydrates uptake and GPR120 and FABP2 associated with fatty acids transport were inhibited. These results indicated that L-theanine could inhibit the glucose uptake by downregulating the related gene expression in the small intestine of rats. Intestinal gene expression of transporters responding to amino acids absorption was stimulated by L-theanine administration.

MeSH terms

  • Amino Acid Transport System ASC / genetics
  • Amino Acid Transport Systems, Basic / genetics
  • Amino Acid Transport Systems, Neutral / genetics
  • Animals
  • Cationic Amino Acid Transporter 1 / genetics
  • Excitatory Amino Acid Transporter 3 / genetics
  • Food Analysis
  • Gene Expression Regulation / drug effects*
  • Gene Expression Regulation / genetics
  • Glucose Transporter Type 5 / genetics
  • Glutamates / administration & dosage*
  • Intestinal Mucosa / drug effects
  • Intestinal Mucosa / metabolism*
  • Lipoproteins, HDL / genetics
  • Minor Histocompatibility Antigens / genetics
  • Rats
  • Sodium-Glucose Transport Proteins / genetics

Substances

  • Amino Acid Transport System ASC
  • Amino Acid Transport Systems, Basic
  • Amino Acid Transport Systems, Neutral
  • Cationic Amino Acid Transporter 1
  • Excitatory Amino Acid Transporter 3
  • Glucose Transporter Type 5
  • Glutamates
  • Lipoproteins, HDL
  • Minor Histocompatibility Antigens
  • Slc16a10 protein, rat
  • Slc1a1 protein, rat
  • Slc1a5 protein, rat
  • Slc2a5 protein, rat
  • Sodium-Glucose Transport Proteins
  • theanine