Is Glutamine Gluten?

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Short Explanatory Video

The short answer to the question “is glutamine gluten?” is “no, it isn't”. According to the Celiac Disease Foundation, gluten is a protein complex found in wheat, cereals, and other cereal products. It is made up of a particular combination of amino acids. Glutamine, on the other hand, is an α-amino acid, one of the building blocks of protein formation.  

What is Glutamine?

Glutamine is the most abundant amino acid in the human body. It is derived from another amino acid, glutamate or glutamic acid, and is combined with ammonia. Glutamine is not an essential amino acid, meaning we do not have to take it in as food since the body can synthesise it; this occurs primarily in the liver. However, it is known as a conditionally essential amino acid because the body uses so much of it. Glutamine comes in two main forms: L-glutamine and D-glutamine.  

A figure showing the 3D chemical structures of L-glutamine (L) and D-glutamine (R).  Rendered using

The Role of Glutamine

It is L-glutamine that has an important role in the body, D-glutamine appears to be largely unimportant biologically. Glutamine is vital to the synthesis of glucose and other amino acids in the body, particularly in the liver and kidneys. Its levels in the body can be decreased during high metabolic activities, such as trauma, sepsis, and inflammatory bowel diseases.1 

People take supplemental L-glutamine for several reasons.

Athletes consume glutamine

It has been shown to improve muscle recovery and reduce soreness after eccentric exercise, making it popular among bodybuilders.2 

However, studies have not supported the contention that it aids immune system function in athletes.3 Moreover, it is used to treat sickle cell disease, as clinical trials have shown it to reduce oxidative cell stress and thus the frequency of pain crises.4

Glutamine can improve the gut health

L-Glutamine has been shown to affect gut health. This involves encouraging the regular replacement of cells lining the intestines and the regulation of the tight junctions between cells, thus ensuring that the gut does not become ‘leaky’ (hyper-permeable), and allowing harmful substances to pass from the intestine into the bloodstream.1 It also has a positive impact on the micro-organisms naturally present in the gut (the microbiome), helping to maintain balance.5,6

Inflammation is at the root of several intestinal conditions, such as ulcerative colitis, Crohn’s disease, and colorectal cancer. L-glutamine has been shown to have anti-inflammatory properties by influencing several mechanisms within the cell.1  

The maintenance of the gut lining is achieved by a balance between new cell formation (proliferation) and old cells dying (apoptosis). When apoptosis outstrips proliferation, several undesirable intestinal conditions can be caused. Ulcerative colitis and coeliac disease, for example, are characterised by increased apoptosis. Glutamine has been shown to have anti-apoptosis properties in the intestine, which could help limit the development of inflammatory conditions, such as coeliac disease.1

Glutamine may help with managing diabetes type-2

In patients with type-2 diabetes, it was reported that glutamine supplementation improved blood sugar and other metabolic processes, but it had a questionable impact on overall glycaemic control.7 Glutamine has also been shown to improve healing of burns, clinical outcomes for intensive care unit (ICU) and surgery patients, and reducing waste in HIV (human immunodeficiency virus) patients in combination with L-arginine and beta-hydroxy beta-methylbutyrate (HMB).8, 10

What is Gluten?

Gluten is a protein complex that strictly speaking, is only found in wheat grains, including spelt, einkorn and triticale. The name gluten is also widely used to refer to proteins in other grains, such as barley and oats; although these are different proteins. Both these types of protein complexes have been linked to coeliac disease (see below).

The gluten complex is made up of a combination of two proteins, a linear (long strand) protein called glutenin, and a globular (folded up) protein called gliadin. The combined properties of these two proteins give bread dough elasticity and workability by forming a network of gluten chains and sheets during the kneading process.

In addition to bread and other cereal foods like crackers and pasta, gluten is present in several other food products, such as soups and sauces, gravy, and due to the presence of barley in the brewing process, it is also present in beer.

Of the two components of wheat gluten, it is gliadin that is toxic to people with coeliac disease.  Gliadin is rich in the amino acids: proline and glutamine, which are difficult to digest. This results in gluten not being completely broken down in the gut and thus leaving behind toxic gliadin oligopeptides (proteins of up to 10 amino acids as opposed to hundreds in a regular protein).  

Most people can handle these with no problem, but in some individuals, it can trigger an autoimmune response known as Coeliac disease. Antibodies against the gliadin oligopeptides cause the release of inflammatory chemicals called cytokines, and inflammation damages the small intestine. Other people can have a wheat allergy or a condition called non-coeliac gluten sensitivity (NCGS), and may experience bloating, diarrhoea, pain and skin rashes as a result of gluten ingestion. However, this may also be a result of fermenting carbohydrates called FODMAPs. Gluten isn’t inherently a “bad” food as many suppose, and has been a vital protein source for thousands of years. It’s just that some people cannot tolerate it, thus they may be suggested to adopt a gluten-free diet.

Coeliac Disease

Coeliac disease affects about 1 in 100 people in the western society and is slowly increasing, but it currently affects far more people in the North African origin. Its origin may be linked to the advent of wheat domestication 10,000 years ago.11 

Coeliac disease is a condition where the body’s immune system attacks and destroys intestinal tissue due to incomplete gluten ingestion, which produces toxic oligopeptides. Such immune attacks lead to inflammation and damage of the villi, which are small finger-shaped projections that line the small intestine and promote nutrient absorption by increasing the surface area. This is called villous atrophy, where the villi shorten and then flatten out. When this happens, nutrients cannot be absorbed correctly and as efficiently into the body.

According to the NHS website, symptoms of coeliac disease include:

  • Foul-smelling diarrhoea
  • Stomach pain
  • Bloating and flatulence
  • Indigestion
  • Constipation

It may also cause:

  • Fatigue, as a result of malnutrition
  • Unintended weight loss
  • Itchy rash
  • Problems getting pregnant 
  • Nerve damage (peripheral neuropathy)
  • Coordination, balance and speech problems 
  • Slow growth and delayed puberty in children

Complications of coeliac disease  include:

  • Weakening of the bones (osteoporosis) 
  • Iron deficiency anaemia
  • Vitamin B12 and folate deficiency anaemia
  • Lactose intolerance
  • Pancreatic insufficiency
  • Intestinal lymphomas and other GI (gastrointestinal) cancers
  • Gallbladder malfunction
  • Other autoimmune conditions

The causes of coeliac disease are mainly genetic. There are specific mutations in the HLA-DQ2 and/or HLA-DQ8 genes which cause autoimmune reactions in response to gluten ingestion.11 People with first-degree relatives who have coeliac disease have a 10% chance of developing it themselves.

Is Glutamine Gluten-Free?

Glutamine is quite different to gluten, although gluten contains a high proportion of glutamine and their names are similar, which is what adds to the confusion. L-glutamine supplements are highly purified and are very unlikely to contain any gluten impurities. This is not the case for so-called glutamine peptide supplements, which are short proteins, maybe derived from gluten grains, and contain potentially harmful gluten impurities.


Gluten is a protein complex found in wheat and other cereal grains. Glutamine is an amino acid which is found in gluten in large amounts; however, the two are not the same despite the similar names. One in 100 people have an autoimmune intestinal condition called coeliac disease, where the gut lining is degraded and destroyed by chemicals called cytokines in response to gluten ingestion. L-glutamine supplements are gluten-free and safe for people on a gluten-free diet.


  1. Kim M-H, Kim H. The Roles of Glutamine in the Intestine and Its Implication in Intestinal Diseases. Int J Mol Sci [Internet]. 2017 May 12;18(5).
  2. Legault Z, Bagnall N, Kimmerly DS. The Influence of Oral L-Glutamine Supplementation on Muscle Strength Recovery and Soreness Following Unilateral Knee Extension Eccentric Exercise. Int J Sport Nutr Exerc Metab. 2015 Oct;25(5):417–26. 
  3. Gleeson M. Dosing and efficacy of glutamine supplementation in human exercise and sport training. J Nutr. 2008 Oct;138(10):2045S – 2049S.
  4. Niihara Y, Miller ST, Kanter J, Lanzkron S, Smith WR, Hsu LL, et al. A Phase 3 Trial of l-Glutamine in Sickle Cell Disease. N Engl J Med. 2018 Jul 19;379(3):226–35.,of%20sickle%20cell%E2%80%93related%20pain
  5. Singh RK, Chang H-W, Yan D, Lee KM, Ucmak D, Wong K, et al. Influence of diet on the gut microbiome and implications for human health. J Transl Med. 2017 Apr 8;15(1):73.
  6. Deters BJ, Saleem M. The role of glutamine in supporting gut health and neuropsychiatric factors. Food Science and Human Wellness. 2021 Mar 1;10(2):149–54.
  7. Jafari-Vayghan H, Varshosaz P, Hajizadeh-Sharafabad F, Razmi HR, Amirpour M, Tavakoli-Rouzbehani OM, et al. A comprehensive insight into the effect of glutamine supplementation on metabolic variables in diabetes mellitus: a systematic review. Nutr Metab. 2020 Sep 25;17:80.
  8. Erdem D, Sözen İ, Çakırca M, Örnek D, Kanyılmaz D, Akan B, et al. Effect of Nutritional Support Containing Arginine, Glutamine and β-hydroxy-β-methylbutyrate on the Protein Balance in Patients with Major Burns. Turk J Anaesthesiol Reanim. 2019 Aug;47(4):327–33.
  9. Wischmeyer PE. The glutamine debate in surgery and critical care. Curr Opin Crit Care. 2019 Aug;25(4):322–8.
  10. Clark RH, Feleke G, Din M, Yasmin T, Singh G, Khan FA, et al. Nutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind, placebo-controlled study. JPEN J Parenter Enteral Nutr. 2000 May;24(3):133–9.
  11. Balakireva AV, Zamyatnin AA. Properties of Gluten Intolerance: Gluten Structure, Evolution, Pathogenicity and Detoxification Capabilities. Nutrients. 2016 Oct 18;8(10). Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Dr. Richard Stephens

Doctor of Philosophy (PhD), Physiology/Child Health
St George's, University of London

Richard has an extensive background in bioscience and bioinformatics with a PhD in membrane transport physiology and 28 years of experience in scientific publishing, bioscience research and computational biology.
On moving to Cambridge, UK, in 2015, Richard took the opportunity to broaden the application of his scientific background as well as to explore new avenues of interest. Among other things he mentored students at the Disability Resource Centre at the University of Cambridge and is currently working as an educator, pro bono for the Illuminate charity whilst further developing his writing and presentation skills.

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