What is Glutamine?

Glutamine is the most abundant amino acid in the body and is involved in more metabolic processes than any other amino acid. When the body does not have a readily available source of glucose, the body converts glutamine into glucose. Glutamine serves as a source of fuel for the cells lining the intestines, and without it, these cells may waste away. It is also important for immune function, as it is important for the function of white blood cells. In animal research, glutamine has shown anti-inflammatory effects. Glutamine is found naturally in high-protein foods such as meat, fish, beans, and dairy products.

The proven roles of glutamine include:

  • promoting gut mucosal integrity by acting as an energy source and preventing bacterial translocation;
  • providing a major fuel source for cells of the immune system; and,
  • improving nitrogen balance in times of stress.

Who may be helped by Glutamine supplements?

In healthy individuals, almost all tissues in the body synthesize glutamine. However, in metabolically stressed individuals there is an increased demand for glutamine, making supplementation essential. This includes people with acute or chronic bowel disease, burns, trauma, sepsis, or immune disorders, and can include people with temporary increased metabolic needs resulting from extreme physical activities. You should consult a physician for the supplemental use of glutamine for the support of serious health conditions.

In both healthy and stressed individuals, glutamine is a fuel source for cells in the small intestine and large bowel. It is the preferred fuel source by the gut and is necessary for the maintenance of gut villi therefore preventing bacteria from entering the small intestine or bowel wall.

Evidence shows glutamine supplements may benefit the following conditions:

  • Crohn’s disease: Patients with Crohn’s disease have been shown to benefit from oral glutamine, especially in preventing gut permeability associated with taking indomethacin.
  • Celiac disease: Ongoing studies on active celiac disease are proving beneficial as these patients often have protein losses and increased glutamine utilization.
  • Short Bowel Disease: One study demonstrated enhanced nutrient absorption with glutamine and growth hormone administration in people with short bowel disease. Glutamine may reduce diarrhea symptoms in patients with short bowel disease because it aids in the re-absorption of sodium and water.
  • Cancer: Some cancer patients receiving chemotherapy have shown relief of mucositis when using oral glutamine as a mouth rinse.
  • Gastritis: Gastritis is a broad term for inflammation of the stomach lining (mucosa). Many factors contribute to the cause of this condition and, in some cases, it may lead to an ulcer. Glutamine has been shown to increase blood flow to the gut, thereby helping the healing process.
  • Major Illness/Surgery: Patients in surgical intensive care units may develop gastrointestinal problems related to glutamine deficiency. Glutamine (often combined with other nutrients) might also be useful as a nutritional supplement for people undergoing recovery from major surgery or critical illness.

How is Glutamine administered?

You can purchase oral glutamine in health food stores, some pharmacies, and via the internet. One such product is Resource GlutaSolve® that you can take with foods and beverages, or as a flush through a feeding tube. Depending on the disease condition, the recommended daily dose of glutamine ranges from 15 to 45 grams (average recommendation is 30 grams), for a minimum of five days. GlutaSolve® contains 15 grams glutamine and 90 kilocalories per packet in a tasteless, quick-dissolving powder. It dissolves best in clear liquids (juice, water) and moist foods (pudding, yoghurt, applesauce). You should not mix glutamine in very hot/cold liquids or foods, or in highly acidic liquids.

Glutamine Safety Issues

As a naturally occurring amino acid, glutamine is thought to be a safe supplement when taken at recommended dosages. However, those who are hypersensitive to monosodium glutamate (MSG) should use glutamine with caution, as the body metabolizes glutamine into glutamate. Also, because many anti-epilepsy drugs work by blocking glutamate stimulation in the brain, high dosages of glutamine may overwhelm these drugs and pose a risk to people with epilepsy. In one report, high doses of the supplement L-glutamine may have triggered episodes of mania in two people not previously known to have bipolar disorder. Maximum safe dosages for young children, pregnant or nursing women, or those with severe liver or kidney disease have not been determined.

If you are taking antiseizure medications, including carbamazepine, phenobarbital, phenytoin (Dilantin®), primidone (Mysoline®), and valproic acid (Depakene®), use glutamine only under medical supervision.

Finally, glutamine is not recommended in protein-restricted diets (i.e. end-stage liver or renal diseases).


Some studies on glutamine have shown promising results in patients with metabolic or gastrointestinal disorders. Oral glutamine is well tolerated and easily administered in most liquids or semi-solid foods. For more information regarding oral glutamine (i.e. Resource GlutaSolve®), contact your physician or dietitian.

Mary Flesher, Clinical Dietitian, The Richmond Hospital
First published in the Inside Tract® newsletter issue 143 – May/June 2004
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