How L-glutamine can help heal your gut

L-glutamine is a supplement that I just recently started taking. Why? Firstly, I am always open to trying new things in order to improve my gut health. And secondly, once I dug into the science and learned the multiple benefits it may confer, I couldn’t resist trying it out and sharing my knowledge with you. Studies have shown L-glutamine positive effects in terms of reducing inflammation and helping in exercise recovery, but also in strengthening the immune system and improving IBD and IBS symptoms.

What is L-glutamine? 

L-glutamine is a non-essential amino acid produced by the body but is also found in food.¹ The main characteristic is that it is considered to have immunological and pharmacological effects.² L-glutamine is a major source of energy for intestinal and some immune cells, which makes it very important for overall gut health.

Reasons why you may start taking L-glutamine

For leaky gut syndrome: also known as “intestinal permeability”, is a digestive condition in which bacteria, toxins, and food particles are able to pass through the intestinal wall to the bloodstream. This “leak” may drive immune and autoimmune conditions, such as Celiac disease, diabetes, food allergies, Crohn’s disease, and IBS. L-glutamine helps maintain a proper intestinal barrier (tightening up the openings of the gut lining, thus reducing permeability).^{3, 4}

For inflammatory bowel diseases (IBDs), such as Crohn’s disease and ulcerative colitis. In these conditions, there is an overactivation of the immune system that attacks the intestines. L-glutamine supplementation could help by reducing inflammation.^{5, 6}

For inflammatory bowel syndrome (IBS): IBS symptoms might be enforced by an L-glutamine deficiency. L-glutamine protects mucous membranes of the esophagus and intestines. Especially people with stress-related IBS may also find their symptoms improved. This happens because cortisol is released when stressed, which could lower L-glutamine stores in the muscle tissue.⁷

To improve overall gut health: intestinal and other immune cells use this amino acid as a source of energy to function properly.⁸

To decrease muscle soreness after exercise:⁹ L-glutamine also promotes carbohydrate storage and muscle glycogen resynthesis during recovery.¹⁰

To boost your immune system: a mice study showed how mice with glutamine supplementation had a boost in their immune system and reduced rates of reactivation of herpes infection.¹¹ Another study showed that L-glutamine supplementation reduced the rate of hospital-acquired infections and reduced the length of stay in the hospital.¹²

May help in fatty liver disease: a recent mice study demonstrated that a glutamine supplement protected mice from the progression of liver disease caused by nonalcoholic steatohepatitis (NASH).¹³

How much L-glutamine should you take?

For long-term use (months), 14 grams a day have been shown to be safe.¹⁴ However, this dose can be increased up to 30 grams daily for a few weeks without side effects.¹⁵ For some health conditions, the dosage might be incremented (up to 80 gr/day). It is better to increment the dosage slowly over the course of weeks, so the body can get used to it. Moreover, due to amino acid competition, it is best to take glutamine on its own (with water).^{16, 17}

• Glutamine for leaky gut: studies have used around 30 gr a day for 1-2 weeks.^{18, 19} However, some people might benefit from higher amounts (up to 80 gr).
• Glutamine for healthy athletes: doses of 20-30 grams a day.²⁰
• Glutamine for patients with IBD: 500 mg per kilogram of body weight per day for 2 months has been recommended.²¹ However, doses as high as 42 gr/day for 21 days have been used.²²
• To reduce inflammation: 400 mg per kilogram of body weight per day has been shown to decrease immune cell count, even though L-glutamine was intravenously administered in this study.²³
• For infections: one study administered 30.5 gr of glutamine to critically ill patients and showed a reduction of pneumonia, bacteremia, and sepsis.²⁴

Always remember to consult your doctor before taking glutamine in quantities bigger than 30gr/day.

Is L-glutamine safe in the long term? 

Actually, no. L-glutamine is not a supplement you want to be taking in the long term, as it can cause amino acid imbalances and impair the synthesis of endogenous glutamine. L-glutamine is a very useful supplement to take in short term, especially when noticing gut discomfort, and can be helpful for reducing symptoms of IBS, IBD, leaky gut, food allergies and in exercise recovery. 

Moreover, people with kidney disease, liver disease, or Reye’s syndrome should avoid taking L-glutamine supplements. The same is advised for people with cancer or at risk. This is due to some types of tumor cells feed on L-glutamine.