The intestinal barrier: a fundamental role in health and disease

ABSTRACT

Introduction: The gastrointestinal mucosa constitutes a critical barrier where millions of microbes and environmental antigens come in close contact with the host immune system. Intestinal barrier defects have been associated with a broad range of diseases and therefore denote a new therapeutic target.

Areas covered: This review is based on an extensive literature search in PubMed of how the intestinal barrier contributes to health and as a trigger for disease. It discusses the anatomy of the intestinal barrier and explains the available methods to evaluate its function. Also reviewed is the importance of diet and lifestyle factors on intestinal barrier function, and three prototypes of chronic diseases (inflammatory bowel disease, celiac disease and nonalcoholic fatty liver disease) that have been linked to barrier defects are discussed.

Expert commentary: The intestinal barrier has been investigated by various methods, but correlation of results across studies is difficult, representing a major shortcoming in the field. New upcoming techniques and research on the effect of barrier-restoring therapeutics may improve our current understanding of the gut barrier, and provide a step forward towards personalised medicine.

KEYWORDS:

• Intestinal mucosal barrier
• mucus layer
• intestinal epithelial cells
• intestinal permeability
• tight junctions
• intestinal inflammation
• gut health
• extraintestinal disease

Declaration of interest

S Vermeire has received grant support unrelated to this manuscript from: AbbVie, MSD, and Takeda. SV has received speaker fees from: AbbVie, MSD, Takeda, Ferring, Dr. Falk Pharma, Hospira, Pfizer Inc., and Tilots. SV has received consultancy fees from: AbbVie, MSD, Takeda, Ferring, Genentech/Roche, Shire, Pfizer Inc., Galapagos, Mundipharma, Hospira, Celgene, Second Genome, and Janssen. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

This paper was not funded.