There are a number of amino acids that affect the intestines and are necessary for proper functioning. Several amino acids and gut health are connected; in particular, glutamine (which I will cover more in-depth below), arginine, glutamate, glycine, threonine, lysine, as well as sulfur-containing aminos. These amino acids and gut functioning are important because they act as fuels for mucosa in the small intestine, and also for the synthesis of nitric oxide (NO), intestinal proteins, polyamines, and other products that are necessary for health. Amino acids come from protein foods like meats, fish, and eggs, or from taking supplements. 

What this means—according to a study by WW Wang, SY Quiao, and DF Li—is that glutamine and the other amino acids and gut-promoting effects from these aminos are not only “critical for the absorption of nutrients” but also are required for the “gut integrity, growth, and health in animals and humans.”

The researchers show that amino acids and gut health, in particular, indicate both trophic and cytoprotective effects. Trophic means relating to feeding and nutrition, and cytoprotective means it protects the cells from noxious chemicals and other things that would otherwise bother the intestinal tract and cause health problems.

Amino acids and gut health includes glutamine

According to the researchers RR van der Hulst, MF von Meyenfeldt, and PB Soeters, one of the essential amino acids and gut nutrients is glutamine. This non-essential amino acid (meaning your body can produce it, even though you can also get it through protein foods and supplements), is “an important nutrient for rapidly dividing cells such as cells from the immune system and the gut.”

There are a few conditions that can also cause a lack of glutamine, which can, according to the scientists, result in “functional disturbances of the immune system and/or the gut. Glutamine is produced mainly by the muscle tissue. A decrease in muscle mass during nutritional depletion may result in decreased glutamine production capacity. Furthermore during critical illness, there is an increased demand for glutamine probably as a result of an increased utilization by the immune system.”

Additionally, glutamine as one of the amino acids and gut nutritives, is important because it prevents toxins and/or bacteria from migrating from the gut lumen (the hollow part of the intestine) into the circulation of the system. Not having enough glutamine can deteriorate this barrier within the intestine and would, in this case, require supplementation of glutamine.

Lastly, glutamine (or other amino acids and gut health) may need to be supplemented in case of nutritional depletion, parenteral nutrition, or even critical illness.