L-Glutamine is a gut-healing nutrient and is the most abundant amino acid in the body and one of the few nutrients that can cross the blood brain barrier ( Brosnan, JT 2003).
The cells in the gut use L-Glutamine to help maintain the health of the mucosa. In other words, it helps to maintain and enhance the gut’s protective mucosal lining. L-Glutamine is also essential for tissue repair throughout the body. Since, it has this unique feature many athletes exploit this fact to help with muscle repair and the preservation of muscle mass. In a similar fashion these properties can be exploited for use in gut repair.
Glutamine is considered the most important nutrient for healing of ‘leaky gut syndrome’ because it is the preferred fuel for enterocytes and colonocytes (DeMarco VG, Li N et al 2003).
In the gut the lining or epithelium is made of cells. These cells are held together side by side by “tight junctions”. These tight junctions acts as physical and functional barrier against the paracellular penetration of large molecules from the gut (Mitic LL, Anderson JM.1998). Hence, any disruption of these tight junctions can then lead to many gastrointestinal diseases and systemic diseases.
Stress, food allergies, alcohol, antibiotics, malnutrition are some of the triggers that can lead to the development of leaky gut syndrome. Leaky gut or increased intestinal epithelial permeability is associated with the development of several gastrointestinal diseases such as food allergies, IBD and IBS (Berkes J, Viswanathan VK et al 2003).
Since, L-Glutamine enhances these tight junctions and thus it reduces intestinal permeability from various stressors and helps maintain the normal intestinal barrier function it is thus of benefit in these conditions. (Foitzik T, Stufler M et al 1997). It was found that when infant rats were deprived of dietary glutamine it resulted in increase of bacterial translocation (Potsic B, Holliday N et al 2002). This increased bacterial translocation caused by increased gut permeability leads to the inflammation during chronic fatigue syndrome. Glutamine in combination with N-acetyl cysteine and zinc partially restores the tight junction integrity and the resulting inflammation (Maes M, Leunis JC 2008).
Gut healing doses
To allow for gut healing. The usual dose for L-Glutamine is 3,000mg or 3g per day.
People who are insensitive to monosodium glutamate (MSG) should use with caution as they may convert the L-Glutamine to the excitatory glutamate.
People who have seizures should not take L-Glutamine.
Berkes J, Viswanathan VK, Savkovic SD, Hecht G. Intestinal epithelial responses to enteric pathogens: effects on the tight junction barrier, ion transport, and inflammation. Gut. 2003 Mar;52(3):439–451.
Brosnan, John T. (June 2003). "Interorgan amino acid transport and its regulation". J. Nutr. 133 (6 Suppl 1): 2068S–2072S. doi:10.1093/jn/133.6.2068S. PMID 12771367
DeMarco VG, Li N, Thomas J, West CM, Neu J. Glutamine and barrier function in cultured Caco-2 epithelial cell monolayers. J Nutr. 2003 Jul;133(7):2176–2179.
Foitzik T, Stufler M, Hotz HG, Klinnert J, Wagner J, Warshaw AL, et al. Glutamine stabilizes intestinal permeability and reduces pancreatic infection in acute experimental pancreatitis. J Gastrointest Surg. 1997 Jan-Feb;1(1):40–46. discussion 6–7.
Maes M, Leunis JC. Normalization of leaky gut in chronic fatigue syndrome (CFS) is accompanied by a clinical improvement: effects of age, duration of illness and the translocation of LPS from gram-negative bacteria. Neuro Endocrinol Lett. 2008 Dec;29(6):902–910.
Mitic LL, Anderson JM. Molecular architecture of tight junctions. Annu Rev Physiol. 1998;60:121–142.
Potsic B, Holliday N, Lewis P, Samuelson D, DeMarco V, Neu J. Glutamine supplementation and deprivation: effect on artificially reared rat small intestinal morphology. Pediatr Res. 2002 Sep;52(3):430–436.