Glutamine is considered a non-essential amino acid that can be synthesized by virtually all tissues in the human body. A healthy 90-kg individual’s body contains approximately 96 grams of glutamine. The major site of glutamine is the skeletal muscle, which represents approximately 60% of stored glutamine. Rapidly replicating cells such as macrophages and fibroblasts remove glutamine from circulation and utilize it as its primary fuel source.
While glutamine is considered non-essential in healthy individuals, it is considered conditionally essential in metabolically stressed individuals. Injury, surgery, wounds, burns and trauma cause an increased uptake and demand for glutamine that exceed the body’s glutamine stores as well as the body’s ability to synthesize enough glutamine to maintain homeostasis. This adds to the cascade of decline during periods of metabolic stress.
Multiple studies show that the translocation of glutamine from the gut to the liver and spleen creates a deficiency associated with atrophy of mucosa cells and loss of gut immune cells.
This loss of gut integrity has a severe negative impact on wound healing due to decreased nutrient absorption, increased gut permeability and decreased immune function. Multiple studies show that endogenous glutamine supplementation at levels of 0.3 to 0.5 g/kg/d divided across two or three doses significantly increased the height of villi in both jejunum and ileum to restore gut function- an important factor in wound healing.