According to experts at Cincinnati Children’s Hospital Medical Center, the single layer of cells lining your gastrointestinal tract represents the largest and most important barrier between your bloodstream and a hostile external environment. Adjacent cells in this epithelial layer are held together by “tight junctions,” which are complex interconnections that seal the cells together and prevent the passage of potentially toxic molecules into your circulation. Disruption of this barrier, a condition called “leaky gut syndrome,” has been connected to a variety of disease states. Some nutrients, such as glutamine, may help to alleviate leaky gut syndrome.
Cause and Result
The cause of leaky gut syndrome, which scientists call intestinal permeability syndrome, or IPS, is poorly understood. A June 2010 review in “Clinics” suggests that immune cells in the intestinal lining produce inflammatory molecules that disturb tight junctions and permit passage of potentially toxic substances. The review’s authors note that IPS has been linked to irritable bowel syndrome, celiac disease, inflammatory bowel diseases, allergies, asthma, type 1 diabetes and even autism.
Diet and Leaky Gut
Scientists at the University of Burgundy in Dijon, France, have demonstrated that fats, sugars and certain compounds introduced into foods by processing and cooking cause degradation of tight junctions. This allows increased passage of substances that would normally be blocked by a healthy intestinal barrier. Once these compounds gain access to your system, they cause widespread inflammation, vascular damage and other adverse metabolic effects. Glutamine may help to protect and repair tight junctions.
Glutamine is one of 20 amino acids used by your cells to manufacture proteins and other essential molecules. Glutamine’s small size and chemical structure allow it to be transported through your bloodstream without being attached to carrier molecules, and it is easily absorbed through cell membranes and converted to glucose for use as an energy source. According to the March 2010 issue of “Inflammatory Bowel Diseases,” the cells lining your intestine are avid consumers of glutamine, which they burn for fuel. Furthermore, glutamine appears to be essential for maintaining the integrity of tight junctions and preventing leaky gut syndrome.
Several studies have demonstrated glutamine’s usefulness in reducing intestinal permeability and ameliorating leaky gut syndrome. When applied to layers of intestinal cells in tissue culture, glutamine enhances the integrity of tight junctions and reduces their permeability. Glutamine supplementation in malnourished children improves intestinal barrier function. Oral glutamine supplementation has also proved beneficial for improving intestinal barrier function in critically ill and injured patients.
The optimal dose of glutamine for leaky gut syndrome is still a matter of some debate. Doses used in human studies vary from 8 g to 25 g daily. Clinical trials using 0.3 g per kilogram per day in low-birth-weight infants – about 20 g daily for a 150-lb adult – evoked a decrease in intestinal permeability. Ask your physician if glutamine supplementation could be useful for you.