Glutamine and Its Role in Gut Health
Glutamine is the most abundant amino acid in the body, with a critical role in human health. It acts as an intermediary in energy metabolism and is a substrate for synthesising glutathione, neurotransmitters, and nucleotide bases.
Glutamine is a nonessential amino acid, but recent observations suggest it may be “conditionally essential”, particularly during illness. Intestinal, immune, and renal cells utilise substantial amounts of glutamine, so levels are often reduced during illness.
Glutamine amino acid is vital in intestinal health.
Studies indicate that the small intestine absorbs one-fourth of plasma glutamine that passes through the organ. Glutamine maintains intestinal barrier function in the gastrointestinal tract, modulates inflammation and apoptosis, and regulates stress responses.
Studies show that glutamine is necessary for intestinal cell proliferation by activating multiple mitogen-activated protein kinases (MAPKs) that influence cell differentiation and other cellular functions. Glutamine also enhances the effects of growth factors, such as epidermal growth factor (EGF) and insulin-like growth factor-1 (IGF-1).
Glutamine modulates tight junction proteins.
In an animal study, a glutamine-enriched diet significantly enhanced IGF-1–mediated DNA and protein synthesis in the presence of short bowel syndrome. In addition, glutamine plays a role in modulating specific proteins related to tight junctions, which are critical to intestinal integrity.
Research indicates that lifestyle interventions and treatment with nutrient supplementation may support intestinal health in the presence of gastrointestinal conditions such as ulcerative colitis (UC).
A recent animal study investigated the efficacy of glutamine supplementation and physical exercise in the presence of UC. Unintended weight loss is a characteristic problem in UC, and supplementation with glutamine in this study prevented body weight loss. Glutamine participates in the immune defence of the intestinal mucosal barrier and aids in the formation of immunoglobulins, particularly immunoglobulin A.
Glutamine slows mucosal damage.
Supplementation with glutamine was shown to slow hemorrhagic damage and severity of macroscopic damage. Additionally, pro-inflammatory cytokines, such as interleukin-6 and tumour necrosis factor-alpha, were attenuated in the presence of glutamine supplementation. Of note, the results of this animal study indicate that moderate exercise may have beneficial effects on colonic mucosa similar to those of glutamine.
In the presence of catabolic conditions, such as infection, cancer, sepsis, surgery, and trauma, endogenous glutamine may not meet the body’s demands. Glutamine plays an inflammatory modulation role, tight junction support, intestinal cell proliferation, and cellular metabolic functions throughout the body. Supplementation with glutamine may support many critical functions within the human body, including the health of the intestinal mucosa.
By Colleen Ambrose, ND, MAT