Your gut is the cornerstone of your health. Modern health problems such as autoimmune disease, mood disorders, hormonal imbalances, headaches, insomnia, fibromyalgia, Alzheimer’s and heart disease have all been linked to a damaged/leaky gut. Whilst many believe that digestive symptoms needs to be present, I see correlations with an array of different health problems without the presence of common gastrointestinal symptoms such as bloating, indigestion, constipation, etc.

The gut is not only responsible for absorbing nutrients, but also to act as a barrier against toxins and bacteria. When the gut is damaged or leaky, the tight junction proteins might allow undigested food particles and other toxins to enter the blood stream. This can cause havoc in your body and lead to chronic inflammation, autoimmune disease and more. L-glutamine is a powerful amino acid (protein) that can improve the health of your gut.


Glutamine and the gut

What is L-glutamine

L-glutamine is a non-essential and conditionally essential amino acid. You obtain essential amino acids from your diet, whereas your cells synthesise non-essential amino acids. Your body can therefore usually synthesise sufficient amounts of glutamine, unless you are exposed to periods of intense physical and emotional stress, trauma, sepsis, diarrhoea or inflammatory bowel diseases. During these times, the loss of L-glutamine might be too high and as a result supplementation might be required.

Deficiency of L-glutamine can compromise the barrier function of the gut and lead to chronic inflammation and a host of health problems.

How does L-glutamine promote gut health?

The surface area of your gastrointestinal tract, if spread out, is about the size of a tennis court! That is a weird thought right?! Special cells, known as enterocytes, cover this ‘tennis court’ area. These cells constantly regenerate, resulting in an entirely new gut every 2-3 weeks if you are healthy. How cool is that?!

It is believed that these cells renew every four to five days and that a continuously high level of cell proliferation is needed to maintain homeostasis. Sadly, it is not as quick if your body and gut is unhealthy. Studies suggest that it can take 12 weeks or longer if you have inflammation, SIBO, viral infections, autoimmune or other chronic health conditions.

In order for these enterocytes to work efficiently, they rely heavily on L-glutamine as their main source of fuel. L-glutamine also helps to regulate tight junction proteins, suppress pro-inflammatory signalling pathways, thereby helping to reduce inflammation. Thereby, making L-glutamine a must-have to optimise your gut health.

Benefits of L-glutamine

The benefits of L-glutamine is far reaching and goes beyond just acting as the key fuel for enterocytes. It also helps to:

  • Maintain intestinal mucosal integrity
  • Modulate the body’s response to inflammation
  • Increase energy metabolism
  • Stimulate immunity by improving secretory IgA
  • Biosynthesis of nucleotides (nucleotides are needed for cell replication and growth)
  • Reduce levels of ammonia
  • Support detoxification

Glutamine and your gut

Always Food First

Ideally you want to ensure that your body is getting sufficient levels of L-glutamine by including the right foods into your diet. This is especially true during periods of stress, illness and exercise. Fortunately, there are many great food sources high in L-glutamine. These include:

  • Bone Broth
  • Dairy
  • Fish
  • Chicken
  • Eggs
  • Beef
  • Red Cabbage
  • Sauerkraut
  • Asparagus
  • Whey protein powder
  • Kale
  • Pulses

When can L-glutamine be helpful?

1. Optimise Gut Health

One of the 5-key steps in healing the gut, involves repairing the lining of the gut. As previously mentioned, L-glutamine has the ability to improve the integrity of the intestinal mucosa, whilst supporting enterocyte proliferation. Various studies have investigated the use of L-glutamine as a way to improve leaky gut.

One study in Brazil looked at a group of 107 malnourished children (aged between 6 months and 8 years) who were below normal weight. 51 children were given L-glutamine, whilst 56 children received a glycine placebo. The focus of the study was to investigate the use of L-glutamine on wasting status and tissue mass. They found that just 10 days of L-glutamine improved both these markers. The study lasted 17 months and they found that the use of L-glutamine significantly increased weight-for-height and weight-for-age compared with placebo. They also found significant improvements in intestinal barrier function.

There are also many studies highlighting the benefits of parenteral L-glutamine in people with inflammatory bowel disease.

2. Reduce severity of diarrhoea

L-glutamine can support the body to prevent fluid loss and prevent dehydration. It does this by regulating cells to absorb water across the junction between the intestine and blood stream. When water is not absorbed back into the body, it results in diarrhoea. L-glutamine can reduce the frequency and severity of diarrhoea. It could therefore be a great first-aid tool in instances of diarrhoea.

3. Support detoxification

L-glutamine is an important energy source for lymphatic cells. The lymphatic system helps to maintain fluid and protein balance in the body. Lymphatic cells also carry immune cells and play a key role in filtering out toxins held in the tissues. L-glutamine helps to support the lymphatic system to remove toxic debris from the body. L-glutamine can therefore potentially benefit individuals with Fibromyalgia, M.E and Chronic Fatigue Syndrome, as their lymphatic systems are often struggling.

4. Exercise

L-glutamine has made a name for itself as a muscle building supplement. Sadly the research does not support these claims.

Prolonged exercise and periods of heavy training are associated with a decrease in plasma glutamine concentration. This decrease is the potential cause of exercise-induced immune impairment and increased susceptibility to infection in athletes. Studies using glutamine to examine it’s immune modulating benefits have not really found the acclaimed benefits in supplementing during exercise.

A literature review of 55 studies found that glutamine supplementation improved some fatigue markers, such as increased glycogen synthesis and reduced ammonia accumulation.

Elevated ammonia, one of the products of protein metabolism, is associated with fatigue. Fatigue also usually occurs when levels of muscle glycogen decreases. It is clear that L-glutamine exert a positive effect on reducing ammonia and increasing glycogen, thereby potentially reducing fatigue. This review, did however highlight that L-glutamine did NOT increase physical performance.

5. Post-surgery recovery

Parenteral L-glutamine supplementation has delivered some positive outcomes for critically ill or surgical patients. These benefits include a reduction in complications associated with hospital acquired infections and shortening the length of stay in hospital.

When to avoid glutamine


Many cancer cells primarily depend on glucose and certain amino acids, such as glutamine for their growth, proliferation, and survival. It is therefore always best to avoid L-glutamine in the presence of cancer.

When should you supplement?

It can often be difficult to know when to reach for a supplement. After all, you should in theory be able to get most of your nutrients from food. The answer really depends on your current health and especially your gut health. If you are looking for a gut reset and don’t really present with any symptoms in general, then some bone broth and sauerkraut can be a great start. If you know you are dealing with chronic health problems, then L-glutamine might give your body a bit of a health boost, but ideally you want the advice of your health care practitioner.

A really important point to note is that not all supplements are created equal. Above all, the quality and purity of the supplement is key and even more important, it has to comply with regulations. Always check with your nutritional therapist or functional medicine specialist to determine if supplementing is right for you.

If you have any questions about whether glutamine is right for you, then please feel free to leave me a message. I would also love to hear whether you have had positive results using L-glutamine. To conclude, I have had really positive results in my personal and clinical experience using L-glutamine as a powder.

Wishing you all a Happy Wellness Wednesday.

Nutritional Therapist Cheshire, Health, Nutritionist Cheshire, Functional Medicine Cheshire, Rootcause Solution