Glutamine & Gut Heath. Do we need it?

Stress, food allergies, alcohol, antibiotics, malnutrition are some of the factors that lead to leaky gut syndrome. Leaky gut or ‘increased intestinal epithelial permeability’ has been implicated in the onset of several gastrointestinal (GIT) diseases such as food allergies, inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) and coeliac disease, glutamine has been shown to help relive such conditions as it reduces intestinal permeability from various stressors and helps maintain the normal intestinal barrier function, in addition it has an extremely important role in digestion, absorption and secretion.

The gastrointestinal lining serves as a barrier to the transmission of toxins, allergens and pathogens from the luminal (outer layer of the gut) contents into the interstitial tissue. Barrier disruption and circulation of noxious substances induce mucosal inflammation and lead to tissue injury. Tight junctions provide an intestinal barrier function. Mucosal protective factors such as growth factors and nutrients preserve the gut barrier integrity and are beneficial in the treatment of various GIT diseases.

L-Glutamine, the star of the show is the most abundant amino acid, in blood plays a vital role in the maintenance of mucosal integrity. Glutamine, traditionally termed as a nonessential amino acid, is now considered a “conditionally essential” amino acid. Its consumption in small bowel mucosa (lining) exceeds the rate of production during catabolic stress such as trauma, sepsis and post-surgery. In the small bowel mucosa, glutamine is a unique nutrient providing fuel for metabolism, regulating cell proliferation, repair and maintaining the gut barrier functions.

Blood concentration of L-glutamine is significantly reduced under the conditions of extraneous exercise and under severe shock and trauma and although adequate glutamine is produced in the body to maintain the normal physiological functions in the cell, the depletion of glutamine under conditions of exercise and stress makes the body depend on exogenous (outside sources) glutamine to supplement the body glutamine pool to meet the requirement. Therefore, L-glutamine is a conditionally essential amino acid.

Normal range of plasma glutamine level is 500–750µmol/L. Prolonged exhaustive exercise leads to nearly 25% drop in plasma glutamine level. Plasma glutamine level falls also during active phases of IBD with IBS, fasting, blood sugar dysregulation and with untreated diabetes mellitus. In all these cases catabolic stress occurs by rise in plasma cortisol (our stress hormone) and glucagon by enhancing the physiological demand for glutamine for gluconeogenesis. Heavy physical training leads to reduction in plasma glutamine level below 500 µmol/L.

This and any prolonged stressors or trauma leads to a drop in body glutamine pool causing mucosal atrophy (gut lining weakening). Oral Glutamine supplementation is therefore a great way to support healthy GIT mucosal growth.

Glutamine also supports several other protective influences on the gastrointestinal tract and forms an important dietary component to maintain gut integrity, glutamine can therefore be considered one of if not the MOST important nutrient for healing of ‘leaky gut syndrome’.

Due to its multiple roles in the GIT glutamine demand is more than 15g/day, this is obtained mainly from systemic circulation, to support this production adding in food sources such as bone broth, fish, cabbage, spinach, tofu, lentils, beans, beets, peas is recommended (be mindful if IBS/D is active with cabbage, beans, lentils, peas).

When gut health symptoms are problematic additional supplemental support could be of use and is defiantly recommended. A supplemental dose of around 5g/day can be supportive of gut health and repair.

Written by Jess Wharton, Gut Health Nutritionist at Key Nutrition