Protective mechanisms of glutamine in intestinal diseases

Abstract

Glutamine, the most abundant free amino acid in the human body, is a major molecule utilized by intestinal cells. It has been reported that glutamine is involved in intestinal physiology and management of multiple intestinal diseases. In gut physiology, glutamine promotes enterocyte proliferation, regulates tight junction proteins, suppresses pro-inflammatory signaling pathways, helps regain microbiota composition, and protects cells against apoptosis and cellular stresses during normal and pathologic conditions. The promising reported protective effects of glutamine supplementations on different experimental animal models of DSS-induced, TNBS-induced and NSAID-induced colitis, speculated a similar effect on clinical settings. As glutamine stores are depleted during severe metabolic stresses, including those associated with trauma, sepsis, and inflammatory bowel diseases, the effect of glutamine supplementation has been examined in patients to improve their clinical outcomes. In this review, we discuss the physiological roles of glutamine in intestinal health and its underlying mechanisms. In addition, we discuss recent evidence regarding the efficacy of glutamine supplementation in treating intestinal diseases.

Keywords

• glutamine
• intestinal function
• tight junction
• microbiota
• animal models
• inflammatory bowel disease