Celiac disease

Coeliac disease is a serious lifelong intestinal autoimmune disorder caused by intolerance to the protein gluten in the diet. It is an issue of the immune system, where gluten is mistakenly identified by the immunity (as a substance harmful to the body), and the body begins to produce antibodies against it. This leads to damage to the mucosa of the small intestine (= layer of enterocytes) and inflammation of the mucosa. The damaged surface of the mucosa cannot regenerate, and there is a loss (= smoothing) of villi mainly in the area of the jejunum and duodenum.

Gluten is a sticky protein that contains two components:

1. Prolamins.

They cause coeliac disease. Prolamins are found in:

• wheat - gliadin,
• rye - secalin,
• barley - hordein,
• oats - avenin.

Oats do not contain gluten but peptides (avenins), some of which can bind antibodies to gliadin peptides. For this reason, oats are presented for celiacs as a relatively "safe" gluten grain (= showing the lowest toxicity, whereas the highest is in wheat). Intolerance arises only to one protein.

2. Glutelins.

They are more involved in allergy to gluten.

It is said that a typical Western diet contains about 10 g of gluten per day. To trigger coeliac disease, however, only 100 mg of gluten per day is sufficient. For these reasons, an amount of 20-50 mg of gluten (= 10-25 mg of gliadin) per day is considered a safe dose.

Coeliac disease occurs in both children and adults and is often inherited in families from generation to generation. In children, it sometimes manifests in the first months when they start receiving solid food containing gluten (biscuits, bread), or the disease may develop later in life. In adults, coeliac disease commonly appears in cases where they long-term consume a surplus of gluten, to which the human digestive tract, including the immune system, is not adapted and reacts by the onset of this very unpleasant disease.

The development of coeliac disease is not only decided by genetics and the presence of gluten in food but often also by a trigger factor (long-term stress, viral infection, pregnancy...). It is assumed that approximately 1% of the population suffers from coeliac disease, but only about 20% of that number is diagnosed. It can develop at any age and affects women more often than men.

For sensitive individuals, the action of gluten leads to disorders of the surface of the small intestine (villi and microvilli gradually disappear), leading to the deterioration of absorption of nutrients from the diet.
Typical symptoms include:

• stomach nausea,
• bloating,
• diarrhea,
• anemia,
• weight loss,
• increased fatigue,
• dermatitis,
• depression.

An accurate diagnosis is determined by performing a biopsy – a sample of the small intestine is taken and examined.

Some people experience negative reactions (nausea, diarrhea, bloating) after consuming foods containing gluten, but the mucosa of the small intestine is not damaged - in these cases, it is not directly coeliac disease but mostly a "mere" intolerance to gluten.

Influence of Diet on Coeliac Disease

All these problems caused by gluten intake are currently incurable; a gluten-free diet must be maintained. This involves significantly limiting or excluding gluten from the diet.

In relation to the gluten content in foods, 2 categories are defined:

1. Gluten-free.
   Contains up to 2 mg of gluten per 100 g of food.
    
2. Foods with a very low gluten content.
   Contains less than 10 mg of gluten per 100 g.

With a gluten-free diet, it is therefore possible to safely consume gluten-free foods. Foods with a very low gluten content must be accounted for in terms of their used quantity and monitored for the overall share of gluten.

Foods intended for a gluten-free diet are always marked with the crossed grain symbol.

Coeliac disease is often accompanied by other food intolerances (most commonly lactose intolerance), as well as various food allergies. Such findings understandably complicate the approach to diet. Since impaired ability of the intestine to absorb nutrients accompanies coeliac disease, deficiency of certain substances generally occurs, which should be addressed in the diet or supplemented:

• calcium,
• iron,
• B complex vitamins,
• vitamin D.

The potential influence of probiotic organisms on the restoration of damaged intestinal mucosa is being intensively studied. Interestingly, the risk of developing coeliac disease is significantly reduced in breastfed infants.

The practical concept of a gluten-free diet seems simple because gluten grains are essentially replaced by gluten-free ones. However, the coeliac patient must be cautious in their selection due to the risk of "hidden" gluten presence. This is quite a challenge as technologically processed products, to which manufacturers tend to add gluten, are part of the diet. This often includes meat products, including sausages, soy products (sauces, miso pastes), ice creams, ketchups, mustards, confections, and many others.