How does glutamine affect the intestines?

Amino acids, after water, are the most abundant chemical compounds in the body. One of them is glutamine, which is considered one of the most important and versatile amino acids in the human diet. Its role has been well characterised in the context of both gut health and immune system function.

1. The role of glutamine in the body
2. Glutamine in the intestines
3. Glutamine in intestinal disorders

The role of glutamine in the body

A person weighing approximately 70 kg should have about 70 g of glutamine in their body, of which 40–80 g is produced ‘independently’ through metabolic pathways. Approximately 20% of all amino acids in the bloodstream are glutamine (and 40-60% in tissues, including the liver and skeletal muscles).

It is an essential amino acid for newborns and relatively essential for adults, and has numerous metabolic and immunological functions. It participates in the regulation of nitrogen metabolism by improving ammonia transport and regulating pH homeostasis in tissues. It serves as a ‘component’ for the production of biochemical compounds of biosynthetic and antioxidant importance.

Alongside glucose, glutamine is the most important source of energy (in catabolic states) for immune cells such as lymphocytes, neutrophils and macrophages. In cases of certain diseases, metabolic stress or low carbohydrate supply, glutamine levels in tissues may decrease as the liver begins to ‘absorb’ it for energy homeostasis regulation purposes.

Glutamine in the intestines

The latest scientific publications emphasise the role of glutamine in the context of digestive health. It promotes processes related to the proliferation and survival of enterocytes (intestinal cells) by activating specific metabolic pathways and regulating intracellular antioxidant potential. In addition, it improves intestinal ion transport and regulates intestinal barrier function in cases of tissue damage, infection or catabolic states. It has also been shown to have a protective and growth-stimulating effect on intestinal mucosal cells.

Glutamine level disorders in the body (especially in the gastrointestinal tract) are observed, among others, in multiple organ injuries, septic infections, and inflammatory bowel diseases. Sometimes, increasing the supply of glutamine through supplementation can improve clinical symptoms in patients struggling with these disorders. Glutamine metabolism can also be modulated by hormones (e.g. glucocorticoids, insulin, growth hormone), so endocrine disorders are another risk factor for the entire ‘economy’ associated with this amino acid.

Glutamine in intestinal disorders

Although the body produces a certain amount of glutamine, it is important to maintain adequate levels in the diet. A properly composed diet can provide the required amounts of glutamine, but there are numerous physiological and pathophysiological conditions in which supplementation may be a better solution.

Sources:

Wang B, Wu G, Zhou Z, Dai Z, Sun Y, Ji Y, Li W, Wang W, Liu C, Han F, Wu Z. Glutamine and intestinal barrier function. Amino Acids. 2015 Oct;47(10):2143-54. doi: 10.1007/s00726-014-1773-4. Epub 2014 Jun 26. PMID: 24965526.

Kim MH, Kim H. The Roles of Glutamine in the Intestine and Its Implication in Intestinal Diseases. Int J Mol Sci. 2017 May 12;18(5):1051. doi: 10.3390/ijms18051051. PMID: 28498331; PMCID: PMC5454963.