Glutamine is an amino acid synthesized by the body from another amino acid, called glutamic acid or glutamate. It participates in many important physiological functions and is especially important in maintaining digestive health, repairing tissue and promoting healthy immune function. As a supplement in the form of powder or pills it is well known in bodybuilding, used to support muscle growth. It is the most quoted cure for leaky gut syndrome, let’s have a look if there is some substance to it.
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Studies linking glutamine to leaky gut syndrome
The studies listed below confirmed that glutamine:
- improved chemotherapy induced leaky gut syndrome in breast cancer patients 
- not only reduced intestinal permeability in rats but also reduced inflammation and exposure to endotoxins
- decreased intestinal permeability after heat stress 
- improved intestinal barrier in malnourished children of 2-60 months of age
- can decrease intestinal permeability, maintain intestinal barrier and reduce inflammatory response in patients undergoing abdominal surgery
- prevents or reduces the intensity of the increase in intestinal permeability
- improves the prognosis of critically ill patients presumably by maintaining the physiologic intestinal barrier and by reducing the frequency of infections
Typical 200g steak contains approx 5g of glutamine, so 2-3 portions of meat per day would be close to the therapeutic doses used in studies which ranged between about 3 to 30 g divided into several smaller doses.
Dietary sources of include plant and animal proteins such as beef, pork and poultry, eggs, milk, yogurt, ricotta cheese, cottage cheese, raw spinach, raw parsley, and cabbage.
Persons sensitive to monosodium glutamate (MSG) may also want to avoid glutamine supplement, since the body can convert it into glutamate. I will be looking at the link between leaky gut syndrome and MSG in one of my future posts.
 Li Y, Yu Z, Liu F, Tan L, Wu B, Li J. Oral glutamine ameliorates chemotherapy-induced changes of intestinal permeability and does not interfere with the antitumor effect of chemotherapy in patients with breast cancer: a prospective randomized trial. Tumori. 92(5):396-401.
 White JS, Hoper M, Parks RW et-al. Glutamine improves intestinal barrier function in experimental biliary obstruction. Eur Surg Res. 37 (6): 342-7.
 Singleton KD, Wischmeyer PE. Oral glutamine enhances heat shock protein expression and improves survival following hyperthermia. Shock. 2006;25 (3): 295-9.
 Lima AA, Brito LF, Ribeiro HB et-al. Intestinal barrier function and weight gain in malnourished children taking glutamine supplemented enteral formula. J. Pediatr. Gastroenterol. Nutr. 2005;40 (1): 28-35.
 Quan ZF, Yang C, Li N, Li JS. Effect of glutamine on change in early postoperative intestinal permeability and its relation to systemic inflammatory response. World J Gastroenterol. 2004;10(13):1992-4.
 De-souza DA, Greene LJ. Intestinal permeability and systemic infections in critically ill patients: effect of glutamine. Crit Care Med. 2005;33(5):1125-35.