Systematic Reviews
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Pharmacol Ther. May 6, 2015; 6(2): 22-27
Published online May 6, 2015. doi: 10.4292/wjgpt.v6.i2.22
Clinical relevance of intestinal peptide uptake
Hugh James Freeman
Hugh James Freeman, Department of Medicine, University of British Columbia, Vancouver V6T 1W5, Canada
Author contributions: Freeman HJ contributed all to this paper.
Conflict-of-interest: No conflict of interest declared.
Data sharing: No data sharing.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Hugh James Freeman, MD, CM, FRCPC, FACP, Department of Medicine, University of British Columbia, 2211 Wesbrook Mall, Vancouver V6T 1W5, Canada. hugfree@shaw.ca
Telephone: +1-604-8227216 Fax: +1-604-8227236
Received: October 9, 2014
Peer-review started: October 9, 2014
First decision: November 14, 2014
Revised: November 22, 2014
Accepted: March 30, 2015
Article in press: April 2, 2015
Published online: May 6, 2015
Abstract

AIM: To determine available information on an independent peptide transporter 1 (PepT1) and its potential relevance to treatment, this evaluation was completed.

METHODS: Fully published English language literature articles sourced through PubMed related to protein digestion and absorption, specifically human peptide and amino acid transport, were accessed and reviewed. Papers from 1970 to the present, with particular emphasis on the past decade, were examined. In addition, abstracted information translated to English in PubMed was also included. Finally, studies and reviews relevant to nutrient or drug uptake, particularly in human intestine were included for evaluation. This work represents a summary of all of these studies with particular reference to peptide transporter mediated assimilation of nutrients and pharmacologically active medications.

RESULTS: Assimilation of dietary protein in humans involves gastric and pancreatic enzyme hydrolysis to luminal oligopeptides and free amino acids. During the ensuing intestinal phase, these hydrolytic products are transported into the epithelial cell and, eventually, the portal vein. A critical component of this process is the uptake of intact di-peptides and tri-peptides by an independent PepT1. A number of “peptide-mimetic” pharmaceutical agents may also be transported through this carrier, important for uptake of different antibiotics, antiviral agents and angiotensin-converting enzyme inhibitors. In addition, specific peptide products of intestinal bacteria may also be transported by PepT1, with initiation and persistence of an immune response including increased cytokine production and associated intestinal inflammatory changes. Interestingly, these inflammatory changes may also be attenuated with orally-administered anti-inflammatory tripeptides administered as site-specific nanoparticles and taken up by this PepT1 transport protein.

CONCLUSION: Further evaluation of the role of this transporter in treatment of intestinal disorders, including inflammatory bowel disease is needed.

Keywords: Dietary peptides, Peptide transport, Peptide transporter 1, Intestinal inflammation, Drug absorption, Bacterial peptides

Core tip: Intestinal uptake of intact di-peptides and tri-peptides occurs by an independent epithelial transport process for protein assimilation. This carrier may also be used to absorb specific drugs and bacterial peptide products that may result in inflammatory disease.