Glutamine: The Gut Aid & Immunonutrient
Glutamine (L-Glutamine) is the most abundant amino acid in the human body and is rapidly depleted from muscle stores by white blood cells and rapidly dividing cells. The depletion is even more pronounced during severe metabolic stress, including high endurance workouts and major surgery (R). Given the rate of depletion under high-stress conditions, this non-essential amino acid can be considered conditionally essential. †
Research suggests this amino acid acts as a gut health promotor and an immunonutrient. Some studies also show that supplementation with L-Glutamine may play a role as an aerobic performance enhancer and a reaction time booster. †
The Gut Aid
Glutamine has been established as a protective agent for the main consumer [organ] of glutamine in the human body, the small intestine (R). It acts as an anti-inflammatory agent that prevents toxin leakage by stabilizing the intestinal epithelial cell tight junctions upon exposure to stressors. It also works to stimulate and enhance the heat shock response in peripheral white blood cells (R).
For cancer patients receiving radiation as a form of treatment, supplementation with glutamine has been shown to prevent injury and decrease long-term complications due to radiation (R). †
High endurance exercise depletes plasma glutamine levels, which is a problem as it acts as a fuel source for the immune system. Studies have demonstrated that high-intensity exercise, such as running can increase intestinal permeability, which can cause GI tract distress. One study showed that oral supplementation of glutamine inhibited exercise-induced intestinal permeability during exercise in the heat (R). †
Since glutamine is important to the immune system, athletes who constantly undergo prolonged, strenuous exercises are at an increased risk for infection. There is evidence that the immune system is less capable of defending against infection after such intense exercise. A research study that compared a group of participants who consumed a drink containing glutamine against a group that had a drink containing a placebo has shown that, after 7 days, the higher percentage of athletes who reported contracting zero infections belonged to the group that received the glutamine drink (R). †
There is more research to support that “glutamine supplementation reduces the rate of infection, inflammation, length of hospital stays, and mortality, and improves gut barrier function and immune function, especially cell-mediated immunity in critically ill patients” (R). †
Reaction Time Enhancer
Though there isn’t much research to support it, one study that compared basketball players who supplemented with L-Glutamine to those who only had a placebo have found data to support a significant improvement in reaction time in the group that received glutamine (R). †
L-glutamine supplementation has been shown to speed up peak torque recovery and dampen muscle soreness after eccentric workouts (R). A second study confirmed that L-Glutamine improved the time of strength recovery and diminished muscle soreness faster than those who had a placebo, noting that supplementation of glutamine also reduced the magnitude of strength loss (R). †
In a study evaluating the effects of glutamine on dehydrated individuals and the amount of time to exhaustion, it was found that supplementation of L-Glutamine increases the time to exhaustion. “Glutamine appears to increase electrolyte and fluid uptake across the intestines by increasing ion transport through an enhanced signaling pathway within the intestinal mucosal cells” (R). †
† This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.
About the Author: Dennis Thompson is the President of Zenko Nutrition. He graduated from Pennsylvania State University with a B.S. in Biology and has more than 2 years of experience working in a cGMP Pharmaceutical testing laboratory.