Glutamine: A misunderstood amino acid with therapeutic potential.

The article focuses on the role of glutamine, a conditionally essential amino acid, in maintaining small intestine health and intestinal permeability. It highlights that the small intestine metabolizes glutamine from both dietary sources and endogenous production, with approximately 88% of daily glutamine being endogenously produced, largely from muscle protein breakdown. Clinical evidence suggests that oral glutamine supplementation at doses around 30 grams per day—reflecting the amount metabolized by enterocytes—is effective in reducing intestinal permeability, whereas lower doses based on typical dietary intake are not. The article recommends that glutamine supplementation for intestinal disorders should consider total glutamine availability from both endogenous and exogenous sources, with suggested doses of 30–50 grams daily or 0.4–0.7 g/kg body weight, while noting that further clinical trials are needed to refine dosing.