A review by South Korea’s Yonsei University and the University of Florida covered the physiological impact of glutamine on intestinal health, as well as its underlying mechanisms.
The intestine uses 30% of the body’s total glutamine, making it a “key nutrient for the intestine”. Additionally, a quarter of plasma glutamine is absorbed by the small intestine when it passes the organ, and previous studies have shown that the intestine “competes with other tissues for glutamine from the body’s amino acid pool and dietary sources”.
It has also been reported that glutamine has anti-inflammatory properties, which could be useful in treating inflammation-induced intestinal diseases, such as ulcerative colitis, Crohn’s disease, and colorectal cancer.
The review stated that “patients with Crohn’s disease display low plasma and cellular glutamine concentrations, and reduced mucosal glutaminase activity”. It added that the ability of glutamine supplementation to protect the intestinal mucosa in animals with inflammatory bowel disease raises the “possibility of (the) use of glutamine support in human patients”.
However, while several studies reported the favourable effects of glutamine supplementation, its clinical efficacy against intestinal diseases “remains a controversial issue”.
The review concluded that although considerable progress has been made in determining glutamine functions, most of it is “based on observational studies”.
"Additionally, current data from clinical trials do not support the use of glutamine supplementation in patients with intestinal diseases, despite in vitro and animal model studies having shown significant beneficial effects. Thus, future human studies should be more standardized to increase their power," concluded the researchers.
Source: International Journal of Molecular Sciences
“The Roles of Glutamine in the Intestine and Its Implication in Intestinal Diseases”
Authors: Min-Hyun Kim, Hyeyoung Kim