L-Glutamine is a neutral, genetically coded amino acid and is the most common naturally occurring amino acid found in muscle tissue. Over 61% of skeletal muscle tissue is glutamine. Glutamine is not an essential amino acid, as it is a derivative of glutamic acid, which can be synthesized from the amino acids arginine, ornithine, and proline. Glutamine is an important nitrogen-carrying amino acid that may be conditionally essential in certain disease states to support the gut-barrier and immune function as well as overall protein use. Colonic irrigations with short-chain fatty acid (SCFA) preparations have demonstrated enhanced healing of bowel tissue in animals and human beings. Dietary fibre supports bacterial SCFA production, normal stool output, and the gut-barrier and immune function. Glutathione (GSH) is a major antioxidant that protects tissues from free-radical injury. Glutamine augments host defenses and may be important in GSH synthesis.