For SURGERY RECOVERY, L-glutamine stimulates wound healing and the formation of new protein, slows breakdown of tissue proteins, and is an energy fuel for muscle cell division. Glutamine is a primary metabolic fuel for the rapidly proliferating cells involved in wound repair. After surgery, tissues need much higher glutamine levels for repair because elevated cortisol from trauma and stress depletes glutamine reserves. Taking extra L-glutamine reduces complications after surgery, and lessens overall hospital stay times.
Plasma glutamine levels may decrease by 58% during critical illness and after surgery, and they remain depleted for up to three weeks. Therefore, L-glutamine is needed to maintain healthy post-operative tissue repair and immune cell function.
What is L-glutamine?
L-glutamine is an amino acid, a protein building block that exists in two forms: D- and L-glutamine. Among the 20 amino acids detailed in the genetic code, glutamine is one of the most versatile for amino acid metabolism and immune function. The biologically important form is L-glutamine. The body naturally produces modest levels of L-glutamine, but it is considered a “conditionally essential” amino acid because we need large amounts during stress, and because it can only be synthesized by some cell types under certain conditions. Glutamine is a precursor for making the body’s “master antioxidant,” glutathione, which protects traumatized tissues from oxidative injury.
“A healthy, unstressed body is highly efficient at making all the glutamine it needs. But for surgery healing, or times of stress or trauma, when we cannot meet the greater demands, then we must ingest it.”
Dr. Rachelle Herdman, Custom Health Guide
L-glutamine is the most abundant amino acid in the human body, making up 30 to 35% of the amino acid nitrogen totals in the blood and other body fluids. Glutamine is a key molecule in new tissue formation, repair of injuries, and energy production, and it contributes to many critical biochemical reactions. It also supports good blood circulation for optimal wound healing.
After injury, the body cannot produce optimal amounts of glutamine, therefore supplementing can be beneficial for recovery and immune health. There is a robust body of evidence supporting the association between L-glutamine supplementation, and improved injury and wound healing.1,2
Where is L-glutamine found?
There are modest amounts of glutamine in a well-balanced diet that contains a variety of vegetables, nuts, and lean sources of protein, usually enough to meet the nutritional needs of an average sedentary or mildly active person. For example, a serving of egg, tofu or beef can provide about 500 mg. But surgery recovery puts greater demands on body systems, creating increased L-glutamine needs that cannot be met through diet alone. Cooking can also destroy glutamine in certain foods, especially vegetables.
How does L-glutamine work in the body?
L-glutamine is commonly stored in muscles and released into the bloodstream during times of physical stress. Glutamine is especially important following tissue trauma and breakdown, or from the catabolic stress of surgery and of critical illness when the body’s glutamine consumption exceeds the normal supply.
In health and disease, the consumption of glutamine by immune cells is similar or greater than glucose. Lymphocytes, neutrophils, and macrophages utilize glutamine at especially high rates under catabolic conditions, such as recovery from wounds or surgery.3
Glutamine is considered anabolic for skeletal muscle, meaning that it encourages muscle to repair and build up. It plays essential roles in pH regulation, maintaining a healthy alkaline-acid balance, and in gluconeogenesis, providing a steady glucose supply to healing tissues. There is evidence that elevated adrenal hormones including cortisol deplete glutamine reserves, and that glutamine supplementation boosts tissue repair. In addition, it provides fuel for immune and intestinal cells and helps keep the cell-to-cell connections in the intestines strong.
How L-glutamine improves surgery recovery
L-glutamine enhances wound repair in the following ways:
- After injury or surgical incisions, glutamine is rapidly released from muscle stores to provide fuel to tissues that are healing.
- Glutamine is essential for healthy immune responses and inflammatory activity. It promotes the proper function, proliferation, and survival of immunity cells; and the gene expression of immune system cells depends upon glutamine availability. Glutamine plays a prominent role in the initiation and progression of the inflammatory response.4 It helps immune function in several ways:
- Glutamine is essential for cell proliferation, and it is a respiratory fuel for activated immune cells including lymphocytes, macrophages, and neutrophils.
- Glutamine performs a vital role for immune cells to fight against pathogens. It is utilized at high rates by white blood cells which form the first line of defense at sites of tissue injury or infection. Neutrophil white cells, which combat bacteria, utilize more glutamine than other types such as lymphocytes and macrophages.5
- for inflammation control and both adaptive and innate immunity, glutamine has a very important role. Numerous research studies have shown that it is key for lymphocyte activation.4
- Glutamine maintains a healthy level of inflammation: The production and secretion of pro-inflammatory cytokines through macrophage white blood cells requires a steady supply of glutamine.5
- Glutamine plays essential roles in pH regulation, maintaining an optimal alkaline pH in the blood and tissues of the kidneys and throughout the body. Glutamine is also important in gluconeogenesis, providing a steady glucose supply to healing tissues.
- For digestion, glutamine is crucial to help restore normal functioning after surgery. It is needed by the rapidly dividing, absorptive cells lining the intestine, to meet their high metabolic demand. It also strengthens cell-to-cell connections in the intestines to improve gastrointestinal integrity.
- Glutamine enhances expression of heat shock proteins, which are essential to cell survival under stress. The most basic cell protection mechanism involves production of a highly conserved family of essential proteins, known as heat shock or stress proteins. These heat shock proteins are released after a severe or sub-lethal cell injury. They can induce “stress tolerance” and protect cells against a subsequent stress that otherwise would be lethal.
Many researchers have found that glutamine can enhance heat shock protein production under stress and improve cell survival after injury. Research results confirm the use of glutamine to enhance heat shock proteins before a serious clinical stress such as major surgical procedures (e.g. cardiac, vascular, and transplantation) or at the start of critical illness.6
Studies confirm how L-glutamine enhances surgery recovery
Depletion of glutamine has been associated with increased risk of post-operative complications, including infections, organ failure, and death.7 Research studies confirm that glutamine improves post-operative healing, and reduces bacterial wound or systemic infections. Deficiency of L-glutamine is linked with inflammation, oxidative stress, and interruptions in immune system functioning, as well as reduced stamina and poor tissue repair. Glutamine is a precursor for making the body’s “master antioxidant,” glutathione, which protects traumatized tissues from oxidative injury.
A 2017 review collected data on how physiological stress can affect cortisol and immune cell functions. The consequences include transient inflammation of joints or connective tissues; elevation of inflammatory mediators; increases of free radicals that cause oxidative stress; and a higher risk of infections or autoimmune disease. Researchers noted that these effects can be mitigated by L-glutamine.8,9
Studies since 2010 confirm that wound healing requires energy, protein, L-glutamine and other key amino acids including arginine, as well as a variety of vitamins and trace elements.10 Amino acids are building blocks for the body to make healing proteins including collagen, the main molecule which knits fascia and connective tissue together.
With our aging population, surgical wound repair research has been significant in recent years–especially studies addressing glutamine supplementation. From studies performed in vitro and in vivo, it is well known that glutamine is a crucial nutrient for wound healing. Research in 2007 found that glutamine supplementation to patients for 6 days before and 5 days after undergoing colorectal surgery significantly reduced the incidence of wound complications.11
A 2012 study confirmed that for trauma patients suffering from poor wound healing, supplementation of glutamine, in combination with antioxidant nutrients, sped up wound closure compared with patients who received placebo. Additionally, the patients who received glutamine had better tissue oxygen levels and increased oxygen saturation, compared to the placebo group.12
Patients recovering from severe burns have better wound healing with glutamine supplementation. Two important trials found that the rate of wound healing was higher in patients receiving glutamine, compared with controls.13,14 The glutamine group benefited from faster-forming, more complete, stronger scars.
A meta-analysis of several randomized controlled trials published in 2010 in the Journal of Parenteral and Enteral Nutrition, evaluated the benefits of glutamine for surgical patients receiving parenteral nourishment. The glutamine-supplemented patients had shorter hospital stays, reduced by 4 to 5 days. They also experienced a significant decrease in infections and post-operative complications.15
Our patients’ experiences with L-glutamine
In our clinic, our patients recovering from surgery who start L-glutamine pre-operatively and continue for 4 weeks after their procedures report faster wound healing. They also notice fewer gastrointestinal symptoms after anesthetics, a lower incidence of infections, good immune function, and feeling more confidence in their healing process with less anxiety than they had anticipated.
Recommendation: L-glutamine 1,000 to 2,000mg daily total, with any meals, from a vegan source, or as directed by your healthcare provider.
- Melis, Gerdien C., et al. (2004). Glutamine: recent developments in research on the clinical significance of glutamine. Current Opinion in Clinical Nutrition and Metabolic Care, 7(1), 59-70.
- Børsheim, E., Tipton, K. D., Wolf, S. E., & Wolfe, R. R. (2002). Essential amino acids and muscle protein recovery from resistance exercise. American Journal of Physiology-endocrinology and Metabolism, 283(4).
- Newsholme, P. Why is L-glutamine metabolism important to cells of the immune system in health, postinjury,surgery or infection.J. Nutr.2001,131, 2515S–2522S.
- Newsholme P. Why is L-glutamine metabolism important to cells of the immune system in health, post-injury, surgery or infection? J Nutr. 2001 Sep;131(9 Suppl):2515S-22S; discussion 2523S-4S.
- Shah, Ali Mujtaba, Zhisheng Wang, and Jian Ma. “Glutamine Metabolism and Its Role in Immunity, a Comprehensive Review.” Animals 10.2 (2020): 326.
- Wischmeyer, Paul E. “Glutamine and heat shock protein expression.” Nutrition 18.3 (2002): 225-228.
- Wischmeyer PE. Clinical applications of L-glutamine: Past, present, and future. Nutr Clin Prac. 2003;18(5):377-385.
- Nieman, David, and Susan Mitmesser. “Potential impact of nutrition on immune system recovery from heavy exertion: a metabolomics perspective.” Nutrients 9.5 (2017): 513.
- Oliveira GP, Dias CM, Pelosi P, Rocco PR. Understanding the mechanisms of glutamine action in critically ill patients. An Acad Bras Ciênc. 2010;82(2):417-430.
- Guo S. and Dipietro LA: Factors affecting wound healing. J Dent Res 2010; 89:219.
- Oguz M, Kerem M, Bedirli A, Mentes BB, Sakrak O, Salman B, and Bostanci H: L-alanin-L-glutamine supplementation improves the outcome after colorectal surgery for cancer. Colorectal Dis 2007; 9:515.
- Blass SC, et al: Time to wound closure in trauma patients with disorders in wound healing is shortened by supplements containing antioxidant micronutrients and glutamine: a PRCT. Clin Nutr 2012; 31:469.
- Zhou YP, et al: The effect of supplemental enteral glutamine on plasma levels, gut function, and outcome in severe burns: a randomized, double-blind, controlled clinical trial. JPEN J Parenter Enteral Nutr 2003; 27:241.
- Peng X, et al: Clinical and protein metabolic efficacy of glutamine granules-supplemented enteral nutrition in severely burned patients. Burns 2005; 31:342.
- Wang, Yan, et al. “The Impact of Glutamine Dipeptide–Supplemented Parenteral Nutrition on Outcomes of Surgical Patients: A Meta-Analysis of Randomized Clinical Trials.” Journal of Parenteral and Enteral Nutrition 34.5 (2010): 521-529.