Glutamine alpha-ketoglutarate (GAKG) is a compound that combines the amino acid glutamine with alpha-ketoglutarate, a component of the Krebs cycle. The use of glutamine (not specifically GAKG) for "leaky gut syndrome," also known as increased intestinal permeability, has some scientific basis primarily from animal and in vitro studies, with limited human data. Glutamine is a major fuel source for enterocytes (cells lining the gut) and is thought to help maintain the integrity of the intestinal barrier. Some studies suggest that glutamine supplementation may reduce intestinal permeability in critically ill patients or those with certain gastrointestinal diseases (e.g., Crohn’s disease), but robust clinical trials in otherwise healthy adults with "leaky gut" are lacking.

Alpha-ketoglutarate itself has been studied for its role in metabolic and intestinal health, but evidence for its specific use in leaky gut is sparse. The combination of glutamine with alpha-ketoglutarate (GAKG) has not been as extensively studied as glutamine alone. Most claims about GAKG for leaky gut are extrapolated from the known functions of its components rather than from direct clinical trials.

In summary, while there is scientific rationale and some preliminary evidence supporting the use of glutamine for intestinal health, the evidence specifically for GAKG is limited and not robust. The rating reflects the presence of some scientific backing, but highlights the need for more direct clinical evidence.