Non-Celiac Gluten Sensitivity

Differences with celiac disease

Celiac disease is a chronic autoimmune disease of the small intestine , which affects genetically predisposed individuals of all age groups.

In celiac patients, the ingestion of  gluten-containing foods  (containing gluten) triggers an immune response in the intestine, which damages the  mucosa of the small intestine.

From this damage arise the  typical symptoms of celiac disease , which include  abdominal pain , diarrhea and/or   chronic  constipation , growth retardation  (in children),  anemia  and psychophysical tiredness .

Today we have several non-invasive tests available  for the diagnosis of celiac disease , which allow us to evaluate the presence or absence of the typical autoimmune response to gluten; these tests are gradually replacing the test traditionally considered more reliable, i.e. the   intestinal  biopsy (by means of a “tube” introduced into the mouth and guided by a video camera to the small intestine, the doctor takes samples of the intestinal mucosa ). In order to talk about celiac disease, therefore, the presence of strongly suggestive symptoms is NOT enough, but it is always necessary to demonstrate their existence through specific tests. This is a very important aspect, also because sometimes the  symptoms of celiac disease are absent or occur atypically.

We can therefore have celiac subjects who do not show  intestinal disorders . In non-celiac gluten sensitivity, on the other hand, exactly the opposite occurs, i.e. we have the presence of symptoms suggestive of celiac disease despite – following the tests just seen – it is possible to exclude the presence of the disease (no trace of “anti-gluten antibodies ” and no trace of lesions of the intestinal mucosa).

Generally, gluten sensitivity is a less severe disorder than celiac disease.

Differences with wheat allergy

Wheat allergy is an  allergic reaction  to  wheat proteins . The differences compared to celiac disease lie in the type of antibodies involved (as well as in the severity of the associated symptoms): while in celiac disease specific  autoantibodies against tissue transglutaminase 2 (anti-TG2) are involved , in wheat allergy  specific IgE antibodies are involved  for some of its  proteins .

As mentioned, there are also differences at the symptomatological level, given that allergy to wheat is mainly characterized by disorders affecting the respiratory system  ( baker’s asthma ), sometimes with rather violent manifestations (anaphylaxis induced by physical exercise ).

The diagnosis of wheat allergy mainly makes use of  prick tests  and  specific RASTs  .

Symptoms

Non-celiac gluten sensitivity is characterized by intestinal and extra-intestinal symptoms related to the ingestion of foods containing gluten. Such symptoms may include:

• Abdominal pain and  swelling ;
• Alvos changes  (diarrhea or  constipation );
• Dermatitis  ( eczema  and  rashes  with redness and  itching );
• Headache  and foggy mind;
• Fatigue, with or without muscle -joint pain.

All these symptoms typically disappear with the elimination of gluten from the diet, only to reappear after its reintroduction, usually within hours or a few days.

Sensitivity to gluten and irritable bowel syndrome

IBS – better known as  irritable bowel (or colon) syndrome  – is a gastrointestinal disorder of functional origin (NOT pathological). In order to diagnose its presence, it is therefore first of all necessary to exclude any disease potentially responsible for the  typical symptoms of IBS , which include diarrhea and/or chronic constipation,  abdominal pain and cramps ,  bloating  and  flatulence .

Therefore, although the symptoms are similar, a subject with IBS cannot be considered celiac, precisely because this condition must be excluded a priori even before we can speak of IBS.

Theories about the causes of irritable bowel syndrome are diverse and there is some consensus that it is a multifactorial disorder; This means that various causes, of a genetic and environmental nature, would contribute to determining its onset. Among these there would also be hypersensitivity to certain substances introduced with food, commonly responsible for  food intolerances  (gluten,  lactose ,  salicylates  , etc.).

The confirmation of this hypothesis derives from the fact that many people with IBS derive considerable benefits from an exclusion diet, i.e. devoid of the substances mentioned above.

On the basis of these considerations, also confirmed by experimental evidence, it is plausible that a certain percentage of people with IBS (around 25-35%) is affected by non-celiac gluten sensitivity. This condition can be present alone or in a context of  multiple intolerances  .

Causes

Since this is a recently defined disorder, several question marks remain about the causes of non-celiac gluten sensitivity.

According to some authors, non-celiac gluten sensitivity would be the “simple” expression of gastrointestinal disorders ( digestive difficulties  of various nature and/or  dysbiosis ) and/or  eating disorders . If something does not work perfectly in the  digestion of food  and/or in the absorption of the nutrients contained therein, the unabsorbed substances are fermented by the  intestinal microbial flora , with the production of gases , fatty acids and other substances which can trigger the typical symptoms of IBS and NCGS. In case of too abundant and varied meals, intestinal disorders, chronic caloric surpluses compared to the body’s needs, the amount of unabsorbed nutrient  increases significantly, generating the symptoms listed above. At the same time, due to a loss of selectivity of the intestinal mucosa, there could also be an absorption of potentially sensitizing substances, which under normal conditions would be excreted with the faeces . All this to say that a subject considered sensitive to gluten could simply be a person who has been eating “too much and badly” for too long.

Molecular characterization studies, increasingly numerous, are trying to identify markers of the disorder, which however are not always detectable. Preliminary evidence in this area seems to paint gluten sensitivity as a particular congenital immune reaction to gluten, naturally different from that which gives rise to celiac disease.

Diagnosis

In the course of the article we have seen how in subjects with gluten sensitivity it is not possible to demonstrate the presence of either specific antibodies for celiac disease (or for wheat allergy) or the classic lesions of the intestinal mucosa with villous atrophy (possibly present very mildly).

There are currently no internationally recognized scientific tests specifically for the diagnosis of NCGS.

As with IBS, therefore, the diagnosis of non-celiac gluten sensitivity is a diagnosis of exclusion, made after tests for wheat allergy and celiac disease have failed. We also remind you that in order to be able to talk about NCGS, the associated symptoms must disappear following the adoption of a  gluten-free diet  and reappear following the reintroduction of gluten into the diet. It would also be preferable for this reintroduction to take place without the patient being aware of it, so as to exclude a possible  placebo effect .

Treatment

The treatment of non-celiac gluten sensitivity is based on the adoption of a gluten-free diet for a specific period. It is therefore the same intervention reserved for celiac disease, with the difference that in NCGS the suspension of gluten-free diets may only be temporary.

Clearly, in addition to this aspect, it is necessary to re-evaluate, with the help of a professional, nutrition in its entirety, from  food combinations  to any intolerances or hypersensitivity, from the intake of  fibers  to that of  simple sugars , from the consumption of foods of additives to the water supply. Equally important is the evaluation of certain psychological and behavioral elements, such as the level of  physical activity , any family or work stressors and the possible intake of medicines,  laxatives ,  alcohol  and drugs.