Glutamine is one of 20 amino acids used by your cells to manufacture proteins and other important molecules. Due to its small size and chemical structure, glutamine can be carried through your bloodstream without being attached to a transporter protein. Thus, according to a June 2003 review in "The Journal of Nutrition," glutamine is the most abundant free amino acid in human plasma. Among the amino acids, it is the most easily converted to glucose by rapidly dividing cells for consumption as fuel. This latter property may have important implications for people suffering from irritable bowel syndrome.
Irritable Bowel Syndrome
Experts at Middlesex Hospital in Connecticut define irritable bowel syndrome, or IBS, as a condition characterized by abdominal discomfort and altered bowel habits that cannot be readily explained by any mechanical, inflammatory or biochemical disorder. Treatment of IBS is frustrating for physicians and patients, because no clear cause for the disorder has ever been identified. However, the June 2010 issue of "Clinics" states that increased intestinal permeability, or leakiness, has been linked to IBS and suggests that glutamine could prove useful for treating this disorder.
Glutamine in the Gut
The cells that line your gastrointestinal tract are among the most eager consumers of glutamine. These cells not only use glutamine as a primary source of fuel; according to the March 2010 issue of "Inflammatory Bowel Diseases," they need it to support the tight junctions that are critical for maintaining a physical barrier between the non-sterile contents of your intestine and your bloodstream. By inflammatory bowel disease, such as Crohn's disease or ulcerative colitis, this barrier is disrupted, and glutamine has shown promise for improving intestinal integrity and reducing inflammation. Less severe disorders, such as IBS, might also benefit from glutamine supplementation.
Glutamine Sources
Like most amino acids, glutamine can be found in high-protein foods. Red meats, poultry, fish, eggs, dairy products and legumes are good sources. Glutamine supplements are also available. Although glutamine is not considered an essential amino acid -- your body can synthesize it from glutamic acid, ornithine, proline or arginine -- there are certain conditions where it becomes "conditionally essential," meaning you would have to obtain additional supplies from dietary sources. Surgery, trauma, inflammatory disorders, cancer and intense exercise could increase your need for glutamine beyond your body's capacity to manufacture it.
Considerations and Recommendations
Since the link between glutamine and IBS hasn't been firmly established, the optimal dosage of glutamine for this condition is unclear. Single doses of 8 grams were well-tolerated in some studies, and clinical trials administering 0.3 grams per kilogram per day to low-birth-weight infants -- the equivalent of 20 grams daily in a 150-lb. adult -- demonstrated improvement in intestinal permeability. Ask your doctor if glutamine could be helpful for you.
References
- "The Journal of Nutrition"; Interorgan Amino Acid Transport and its Regulation; J.T. Brosnan; June 2003
- "American Family Physician"; Treatment of Irritable Bowel Syndrome; S.K. Hadley, S.M. Gaarder; December 2005
- "Clinics (Sao Paulo)"; Possible Links Between Intestinal Permeability and Food Processing: A Potential Therapeutic Niche for Glutamine; J.R. Rapin, N. Wiernsperger; June 2010
- "Inflammatory Bowel Diseases"; Potential for Amino Acids Supplementation During Inflammatory Bowel Diseases; M. Coeffier, et al.; March 2010
- "NIH Workshop on the Role of Dietary Supplements for Physically Active People"; June 1996
- "Journal of Parenteral and Enteral Nutrition"; The Effect of Glutamine-Enriched Enteral Nutrition on Intestinal Permeability in Very-Low-Birth-Weight Infants: A Randomized Controlled Trial; A. van den Berg, et al.; September to October 2006
