L-Glutamine and glutamine
L-Glutamine is the naturally occurring form of the amino acid glutamine. The names L-Glutamine and glutamine are often used interchangeably. L-Glutamine is one of the only amino acids that can cross the blood-brain barrier. L-Glutamine can be found in both animal and plant-based proteins, including whey protein, meat, chicken, fish, eggs, beans, dairy products, rolled oats, soybeans and fermented foods. L-Glutamine is usually a ‘conditionally’ essential amino acid but becomes ‘essential’ when stores have been depleted, particularly after periods of physical stress.
The role of L-Glutamine in the body
L-Glutamine is necessary to support gastrointestinal mucosal membrane health and for maintaining digestive system health. L-Glutamine is an important fuel source for the intestinal mucosal cells where it helps to maintain the integrity of the intestinal lining and normal gut barrier function and permeability.
The intestinal lining acts a selective barrier, allowing important dietary nutrients, electrolytes and water to enter the bloodstream, while at the same time inhibiting the passage of foreign substances, such as food antigens, toxins and harmful pathogens, into the bloodstream. When the intestinal lining becomes compromised, these foreign substances ‘leak’ into the bloodstream, triggering immune system activation and inflammation. See Gut Care.
Around 80% of the immune system sits within the gastrointestinal tract and L-Glutamine makes a significant contribution to maintaining gut-associated lymphoid tissue (GALT), part of the gastrointestinal immune system. L-Glutamine is an important fuel source for the rapidly multiplying cells of the immune system. It helps support white blood cell function and is particularly beneficial after periods of physical stress where levels of glutamine can become depleted. L-Glutamine also helps to maintain secretory IgA, an immune marker, which functions primarily to reduce the attachment of bacteria to the mucosal cells of the gut. See Gut Care.
Nervous system health
L-Glutamine assists in the production of neurotransmitters and supports nervous system health and function. As L-Glutamine can cross the blood-brain barrier, it is readily taken up by the brain and converted into gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter that helps calm the central nervous system.
L-Glutamine is primarily stored in skeletal muscles and helps maintain muscle health after exercise by maintaining glutamine levels. Requirements for glutamine may be increased in athletes and active individuals. See Muscle Resuscitation.