Glutamine, or L-glutamine, is an amino acid derived from
another amino acid, glutamic acid. It serves as a precursor
to D-glucosamine, an amino sugar well-known for its ability
to relieve pain and inflammation and regenerate connective
tissue in people and pets with osteoarthritis. Severe stresses
may result in a temporary glutamine deficiency.
There is no daily requirement for glutamine as the body can
make its own glutamine. High-protein foods such as meat, fish,
beans, and dairy products are excellent sources of glutamine.
Glutamine plays a role in the health of the immune system,
digestive tract, and muscle cells, as well as other bodily
functions. It appears to serve as a fuel for the cells that line
the intestines (it serves as a primary energy source for the
mucosal cells that line the intestinal tract). Because stress
on the intestinal cells (such as chronic inflammatory bowel
disease) can increase the need for glutamine as the body
replaces the cells lining the intestinal tract, glutamine is often
recommended for pets with chronic bowel disorders including
inflammatory bowel disease. Heavy exercise, infection, surgery,
and trauma can deplete the body’s glutamine reserves,
particularly in muscle cells.
It has also been suggested as a treatment for food allergies,
based on the "leaky gut syndrome." This theory holds that in
some pets whole proteins leak through the wall of the digestive
tract and enter the blood, causing allergic reactions. Preliminary
evidence suggests glutamine supplements might reduce leakage
through the intestinal wall. In people and pets, glutamine is also
recommended to reduce the loss of muscle mass (as may occur
during injury, stress, or high-endurance activities as might be
encountered by dogs competing in field trials).
Glutamine is also a precursor to the enzyme glutamine:
fructose-6-phosphate amidotransferase, which plays a role
in the development of insulin resistance that may eventually
manifest itself as diabetes if there is an imbalance or
deficiencies in glutamine levels. Supplementing diabetic pets
with glutamine may be helpful, although more research is
needed in this area.
Glutamine may reduce the gastrointestinal toxicity of
some chemotherapy drugs. It can also prevent inflammation
of the intestinal tract caused by radiation therapy of this
area. Glutamine should be considered as a supplement for
dogs undergoing half-body irridiation for the treatment of
There is little real evidence that glutamine works as a treatment
for true food allergies, although it is highly recommended for
pets with various bowel disorders.
In people, there is evidence glutamine supplements might
have significant nutritional benefits for those who are seriously
ill. In one study, 84 critically ill hospital patients were divided
into two groups. All the patients were being fed through a
feeding tube. One group received a normal feeding-tube diet,
whereas the other group received this diet plus supplemental
glutamine. After six months, 14 of the 42 patients receiving
glutamine had died, compared with 24 of the control group.
The glutamine group also left both the intensive care ward and
the hospital significantly sooner than the patients who did not
receive glutamine. Adding glutamine to the feeding formulas
of hospitalized pets might be warranted.
Recommended dosages in pets are 250 to 3,000 mg daily.
Maximum safe dosages for young children, pregnant or
nursing women, or those with severe liver or kidney disease
have not been determined; similar precautions are probably
warranted in pets.
Glutamine, being one of the body’s amino acids, is thought to
be a safe supplement when taken at recommended dosages.
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 pets with epilepsy. If
your pet is taking anti-seizure medications, glutamine should
only be used under veterinary supervision.