The safety of oats for people with coeliac disease is controversial. Australia and New Zealand exclude oats from the gluten-free diet due to safety concerns, but many other countries do not. Oat is a nutritious grain that is high in fibre and has a range of health benefits, but it is important to determine if they can be safely consumed by people with coeliac disease.

We have shown that a proportion of people with coeliac disease have T cells that are triggered by oats or purified oats protein (avenin) to promote an inflammatory response, potentially putting them at risk of harm. This study aims to definitively determine if oats are safe to consume in coeliac disease, if safety can be determined by an immune blood test or food test, and whether a specific type or dose of oats is necessary for safe consumption.

This study involves the consumption of contamination-free oats or oat protein, immune blood tests and for some, gastroscopy and biopsy of the small bowel.

Specific susceptibility genes, such as HLA-DQ2 and/or HLA-DQ8, are critical for the development of coeliac disease. However, environmental factors are also important, and they may act as ‘triggers’ of disease. How they might do this is a very important yet unanswered question.

Emerging evidence suggests an important role for the eco-system of microbial organisms in the gastrointestinal tract, termed the ‘microbiome’, in coeliac disease development.  For example, studies undertaken with collaborators Professor Elena Verdu (McMaster University, Canada) and Professor Jamie Rossjohn (Monash University) have implicated Pseudomonas bacteria in coeliac disease development via a number of different mechanisms. This raises the possibility that specific alterations in the microbiome may have an important effect on gluten immunity and could affect the risk for coeliac disease development in genetically susceptible people.

Establishing how well a person is following a gluten-free diet is difficult. Current tools rely on assessing a person’s dietary patterns or using antibody tests or intestinal biopsy, but these only indirectly reflect gluten exposure and they are not very helpful at determining if gluten is still being consumed.

This study is assessing a new technology designed to measure gluten (specifically, fragments of gluten called peptides) in a person’s stool (faeces) or urine. This gluten immunogenic peptide (GIP) assay is highly sensitive for detecting tiny amounts of gluten ingested by a person. They offer the potential to help doctors determine when a person with coeliac disease who is following a gluten-free diet is actually consuming gluten.

Our studies have shown that the GIP test can detect extremely small amounts of gluten present in stool samples and that symptoms and coeliac serology are very poor predictors of gluten intake compared to this sensitive stool test. Many people with treated coeliac disease and normal coeliac serology had evidence of gluten in the stool, indicating unintended gluten exposure. We are now examining why so many people with treated coeliac disease have inadvertent gluten exposure and understand the significance of low level detection.

Early diagnosis of coeliac disease is important because it expedites treatment with a gluten-free diet and the journey to recovery and improved health. The current diagnosis of coeliac disease depends on antibody testing (coeliac serology) and a gastroscopy to sample the small intestine. Both of these tests are only accurate if gluten is being consumed. Unfortunately, many people in the community who may have coeliac disease have started a gluten-free diet, rendering current tests unhelpful for diagnosis. A prolonged gluten challenge is necessary but is often tolerated poorly.

We are developing a blood-based diagnostic test for coeliac disease based on the measurement of a chemical (interleukin-2) that is produced in significant amounts in the blood of people with coeliac disease after exposure to gluten but not those without coeliac disease. Interleukin-2 is also detectable in a test tube when the blood from someone with coeliac disease is mixed with gluten if we employ an ultra-sensitive cytokine detection machine (Figure 1).  Our goal is to develop a blood test to diagnose coeliac disease without the need for a person to deliberately consume gluten or have to undergo an invasive gastroscopy.