Coeliac disease is an autoimmune disease that is triggered by gluten ingestion in genetically predisposed individuals. Autoimmune diseases are where the body’s own immune system starts to attack healthy cells.
Gluten is a general term for proteins found in grains such as wheat, rye, barley, spelt and kamut.
0.5-1% of the general population have Coeliac disease. This makes it is one of the most common autoimmune diseases. However, certain areas such as sub-Saharan Africa and Japan have lower rates. This is understood to be due to low gluten intake and the low prevalence of the genes associated with an increased risk for Coeliac disease. [Source: Pubmed]
Over recent years cases of Coeliac disease have been rising. This may be partly due to the increased sensitivity of Coeliac testing but also likely due to increased ingestion of gluten. Some studies indicate that large sections of the global population are consuming up to 20g/day of gluten. This can be compounded by the reduction in the quality of gluten/gluten-containing foods and a shift to a lower fibre diet. [Source: Pubmed]
Between the years 1975 and 2000 there was a 500% increase in Coeliac disease in the US. [Source: Pubmed]. The prevalence is also increased in those with associated risk factors that include:
- A first-degree relative with Coeliac disease
- Patients with Down syndrome
- Patients with Type 1 diabetes
- Patients with IgA deficiency [Source: Pubmed]
In the Western world, other autoimmune conditions are on the rise for which gluten is not responsible. This has led some researchers to understand that environmental factors other than exposure to gluten are at play. [Source: Pubmed]
What are the symptoms of Coeliac disease?
The symptoms of Coeliac disease are similar to what would be seen in IBS but can extend beyond the digestive system.
The digestive symptoms include:
- Abdominal pain
- Diarrhoea
- Bloating
- Abdominal distension
- Loss of appetite
- Failure to thrive
Is also common for symptoms to appear outside of the digestive system.
These can include:
- Iron deficiency anaemia
- Osteoporosis
There is also the possibility of cognitive neurological involvement in Coeliac disease. This can present with symptoms such as:
- Depression
- Epilepsy
- Migraines
- Tremor
- Ataxia
- Epilepsy
This may be due to the immune or inflammatory processes taking place brain but also as the result of the poor absorption of key nutrients due to the damage in the small intestine. The risk of neurological involvement due to poor absorption of nutrients occurs largely in untreated Coeliac disease.
This can involve the malabsorption of:
- Calcium
- B6
- B12
- Vitamin E
- Folic acid
- Carnitine [Source: Pubmed]
What causes Coeliac disease?
These 2 factors that are most well understood are genetic susceptibility and exposure to gluten.
Incidences of many other autoimmune conditions have risen over recent years. This has led some researchers to question whether or not gluten is the only element responsible for triggering Coeliac disease in the genetically susceptible.
One theory is that improved hygiene with the subsequent lack of exposure to environmental bacteria has impacted the development of the immune system in the gut. This theory then leads to the immune system being ‘poorly trained’ which can then make it more likely to initiate an autoimmune process. [Source: Pubmed]
This is related to the role of the gut microbiome and how it influences the immune system which is understood to be due to the role and the relationship between the gut microbes, the gut lining and the gut immune system.
Several elements may need to be present to result in Coeliac disease which includes:
- Genetic predisposition
- Loss of intestinal barrier function
- An inflammatory immune response to gluten
- Imbalanced gut microbes
- An inappropriate adaptive immune response [Source: Pubmed]
Coeliac disease and genetics
All autoimmune conditions have an increased risk with the presence of disease-specific genes. Coeliac disease is no different with a 10-15% risk of the condition if a 1st-degree relative has the disease. This is as high as 75-80% in identical twins. [Source: Pubmed]
2 specific genes have been associated with an increased risk of developing Coeliac disease. These are HLA-DQ2 and HLA-DQ8. HLA-DQ2 carries an increased risk of 25-30% of disease onset in infants if they also have a first-degree family member with the condition. There are also over 100 other HLA genes that are associated with Coeliac disease [Source: Pubmed]
Coeliac disease diet
Gluten-containing grains were first introduced into the human diet approximately 10,000 years ago during the agricultural revolution. This makes these foods a relatively recent addition to the human diet.
Gluten is a collection of proteins found in certain grains and is resistant to digestion. It is also ingested in considerable amounts in the western world. The combination of its indigestibility and the amount often consumed can partly explain the potential for the immune system to lose the ability to tolerate this protein. [Source: Pubmed]
The only known treatment for Coeliac disease is a strict gluten-free diet. This involves the removal of certain grains as well as products made from those grains.
These include:
- Wheat
- Rye
- Barley
- Kamut
- Triticale
- Spelt
- Durum
- Couscous
- Semolina
- Farina
- Farro
- Einkorn
- Wheat berries
- Bulgur
- Wheat bran
- Wheat starch
- Wheat germ
This also includes the products made from these grains such as:
- Pasta
- Bread
- Cookies
- Granola bars
- Pastries
- Cereals
- Gravies
- Crackers [Source: Celiac.org]
Even though other grains such as oats are technically gluten-free there is the risk of these being contaminated with gluten. This can be the result of either growing or processing conditions and is the reason for certain oat products being labelled as gluten-free. [Source: Pubmed]
Also Read: How To Go Gluten Free
Gut health and Coeliac disease
Even those the rates of Coeliac disease have risen in Western countries the exact reason for this remains unknown. However, the gut ecosystem appears to play a role.
In particular, how the infant’s gut microbiome is shaped during early life. It has been reported in studies that exposure to a wide range of non-pathogenic microbes during early life reduced the risk of developing Coeliac disease.
The factors in early life that can contribute to negative alterations in the gut health of the infant include:
- Delivery by c-section
- Antibiotic usage
- A short duration of breastfeeding
Additionally, breastfeeding may have a protective role, especially if continued alongside gluten introduction. [Source: Pubmed]
Certain changes in the balance of the gut bacteria have also been noted in those with Coeliac disease. In particular, increased levels of the microbial group’s Firmicutes and Proteobacteria. These are both associated with poor gut health.
Some Coeliac patients may also adhere to a strict gluten-free diet but still experience symptoms. This may be due to a persisting elevation in Proteobacteria contributing to altered digestive function.
Other changes have been noted with reduced levels of beneficial microbes such as Bifidobacterium and Lactobacillus. As well as these microbial imbalances a reduction in microbial diversity (a sign of a weakened microbiome) and a reduction in short chain fatty acid production have also been reported. [Source: Pubmed]
SIBO and Coeliac disease
SIBO stands for small intestinal bacterial overgrowth. The large intestine is the location with the highest concentration of microbes while the small intestine should have a more moderate microbial population. However, in SIBO there is an increased number of bacteria in the small intestine.
This can present with the same symptoms that are typically seen in IBS. These include
Bloating, abdominal pain, food intolerances and alterations in bowel patterns.
Studies have examined those with Coeliac disease who still experience symptoms even when following a strict gluten-free diet. A variety of gut issues were found which included:
- Lactose malabsorption (in 14%)
- Giardia lamblia infection (in 8%)
- Roundworm infection (in 8%)
- SIBO (in 70%)
Due to the high prevalence of SIBO in Coeliac disease patients not responsive to a gluten-free diet, it is an area that can be considered. [Source: Pubmed]
Conclusion
Having a family member with Coeliac disease can increase the risk of developing this condition. Additionally, even once diagnosed there may not be a full resolution in symptoms without further support.
An IBS & Gut Health Clinic practitioner can help to guide you through both how to go gluten-free and also how to address other factors that might be contributing to ongoing symptoms, even if a gluten-free diet is already being followed.
