You’ve heard it at the barn. Supplement l-glutamine for gut health. But why?
In this article, when we use the term glutamine, we mean L-glutamine.
◆︎ Use in the muscle:
Glutamine is created in the muscles. The muscles are also the main storage location. When the glutamine is within the cell, it attracts water and sodium, pumping up the muscle cell. This hyperhydration acts like an anabolic signal, stimulating muscle synthesis pathway and inhibiting protein breakdown.
During times of extreme stress, such as trailering, heavy training, surgery, or significant illness or injury, glutamine is transported out of the muscle cells faster than the muscles can create new glutamine. This depletion of glutamine in the muscles reduces the water volume, stops the new muscle synthesis, and encourages muscle breakdown.
◆︎ Use in the liver:
During systemic inflammation,the liver uses massive amounts of glutamine to create glycogen and to create proteins that fight off the threat. The glycogen created by the liver does not spike insulin and is a fuel used by the liver and muscles.
◆︎ Use in immune system regulation:
Lymphocytes and macrophages cannot create their own glutamine. When fighting an infection, they multiply rapidly. They use glutamine that is circulating in the bloodstream for cellular replication.
◆︎ Why would we need to supplement glutamine instead of just feeding more hay that contains the precursors?
During periods of extreme challenges, the limiting factors are the enzymes that create the glutamine. By feeding glutamine directly, we bypass those enzymes. This allows the cells of the lining of the intestines to directly use the glutamine consumed for energy.
◆︎ Which horses are most likely to benefit from glutamine supplementation?
➡ Horses with digestive issues or ulcers
➡ Horses in heavy exercise for muscle recovery
➡ Horses that are stressed, such as trailering or changing herd dynamics
➡ Older horses
➡ Horses that are systemically challenged, such as
▪ Sick horses
▪ Following surgery
▪ Fighting infection
◆︎ How much glutamine can I feed my horse?
Maintenance:10 grams per day. Helps maintain healthy gut functioning.
Heavy training: 10-20 grams per day, preferably in 2 or 3 feedings. Helps to replenish glycogen without spiking insulin, helps prevent muscle wasting, and supports immune function.
Post surgical or acute illness: 20-30 grams per day, in 2 or 3 feedings. Provides direct energy for the cells lining the intestines, upregulates intestinal tight junctions, and supports glutathione production.
Supplementation:
L-Glutamine is available as a single amino acid.
Equine Gut Support already has glutamine included in it.
◆︎ Consult your veterinarian:
While we can nutritionally support our horses, there are times that veterinary intervention is necessary. Consult your veterinarian if you are not seeing sufficient results with nutraceutical support.
We do the best we can for our horses. Understanding our horse's needsis a part of that.
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Disclaimer: Statements regarding dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease or health condition.
©Joan Kulifay, MSc. 2026