Casein Glycomacropeptide (CGMP) is a bioactive peptide derived from casein during cheese production. Its potential application in supporting or treating Leaky Gut Syndrome (increased intestinal permeability) is rooted in a modest but growing body of scientific research. Animal studies, particularly those involving mouse and rat models, have demonstrated that CGMP can exert beneficial effects on gut health. These include anti-inflammatory properties, modulation of gut microbiota composition, and protection of the intestinal barrier, which theoretically could support individuals with leaky gut. Specifically, CGMP has been shown to increase the expression of tight junction proteins and reduce endotoxin-induced permeability in some preclinical models.

However, direct clinical evidence in humans with diagnosed Leaky Gut Syndrome is limited. Most studies to date have been preclinical or have focused on broader gut health outcomes, such as its use in phenylketonuria patients or its prebiotic effects. No large, well-controlled clinical trials have specifically assessed CGMP for leaky gut in humans. Therefore, while there is some scientific rationale and preliminary evidence supporting its use, the evidence base is currently weak (rated 2/5). Further research, especially human studies, is needed to clearly establish its efficacy and safety for this application.