ABSTRACT
Glutamine is the preferential substrate of rapidly dividing cells such as epithelial cells and immune cells, that is, lymphocytes. Approximately 60% of absorbed glutamine is oxidized in the small intestine to provide energy. To document the effects of glutamine on intestine in physiological situation, one has to consider whether glutamine is acting by itself and/or through its metabolism and on what cell type in the intestinal mucosa the amino acid is active. In addition, the intestinal microbiota both in the small and large intestine may impact the metabolism of glutamine released in the process of protein digestion from alimentary and endogenous proteins. In various pathological situations, there are some indications that glutamine supplementation may benefit the intestinal mucosa. The chapter focuses on the metabolic and physiological effects of glutamine on the intestine in both healthy and several pathological situations in which the intestinal mucosa integrity is altered.
