What happens in celiac disease and how is it treated?

When we eat, we chew our food into small pieces that then pass through our stomach into our upper small intestine – also known as the duodenum. There it is broken down into its smallest units, including many nutrients. Thanks to finger-like protrusions (villi) in the lining of the duodenum, it has a large surface area and can easily absorb nutrients. If a part of gluten called gliadin passes into the small intestine, it is converted by an enzyme in our body called tissue transglutaminase (tTG or TG2).

The immune system can tell whether substances absorbed by the lining of the intestine are harmless or have to be attacked. Some of the immune system cells involved have HLA molecules on their surface.

The genes of people with celiac disease have sections with the HLA types DQ2 or DQ8, or both. Their immune system reacts to the gliadin in gluten. Certain immune system cells known as T-lymphocytes (or simply "T-cells") cause plasma cells to make antibodies against gliadin. The plasma cells also make antibodies against a natural protein in the body called transglutanimase (tTG): These "auto-antibodies," which attack healthy cells in your body, can be detected in the blood and are a clear sign of celiac disease.

The autoimmune reaction can cause problems in various parts of the body. But it always causes an inflammation in the mucous membrane lining the intestine. If the inflammation persists, the tissue in the lining of the intestine changes: The villi get flatter, which reduces their surface area. As a result, the small intestine absorbs less and less nutrients, which leads to deficiencies.

Only about 2 out of 100 people who have the genes associated with celiac disease actually have the disease. This means that other factors must play a role, too. The following are considered to possibly increase the risk of celiac disease: gastrointestinal infections (tummy bugs), taking antibiotics during pregnancy or in early childhood, and changes to the microbiome in infants. But research in this area has not led to any clear conclusions. There is no reason to believe that vaccinations cause celiac disease.

Another possible connection that is under discussion is the introduction of gluten to baby food. But there is currently no proof that giving babies gluten-containing food at the age of 6 months already, rather than waiting until they're 12 months old, makes a difference to the risk of developing celiac disease in childhood or adulthood.

The only treatment for celiac disease is a gluten-free diet. But it is a very effective treatment. Digestive problems often improve within a few weeks. About two thirds of those affected no longer have any symptoms after six months. People who have celiac disease without the typical digestive problems still need to follow a gluten-free diet, though.

Other celiac disease symptoms are often overlooked – such as stunted growth in children, problems finding the right insulin dosage in people with type 1 diabetes, and unexplained infertility. They, too, can sometimes be improved by following a gluten-free diet.

There are currently no other treatment options for celiac disease apart from a gluten-free diet. Some people find that home remedies such as chamomile tea and hot water bottles soothe their symptoms, but they do not influence the disease itself.

Researchers are looking into various possible treatment approaches. For example, they are working on the development of a type of modified wheat that is safer for people with celiac disease. They are also looking into medications to influence the immune system reaction in the small intestine. But most of the research is in the early stages, so it could still take a good few years until the results can be applied.

Various products containing enzymes that break gluten down are offered as dietary supplements. But experts advise against taking them because there is a lack of research on the exact effects of these products in people with celiac disease.