24 blood proteins reveal gut inflammation in coeliac disease

Twenty-four specific proteins found in the bloodstream may provide clearer indicators of gut health for individuals managing coeliac disease, according to research conducted by the University of Oslo’s Faculty of Medicine. The study suggests these molecular markers could help track disease progression more accurately than current standard tests, particularly regarding persistent intestinal inflammation.

Biomarkers track intestinal damage

Coeliac disease is an autoimmune disorder where the immune system reacts negatively to gluten. Consuming this protein triggers inflammation that can harm the intestine and reduce its capacity to absorb nutrients. While strict avoidance of gluten remains the primary treatment, many patients face uncertainty because existing blood tests often fail to clearly show whether inflammation or physical damage continues despite dietary compliance.

Jostein Holen Ibsen, a PhD fellow and physician at the Norwegian Coeliac Disease Research Centre and Oslo University Hospital, noted that diligent adherence to a gluten-free diet does not always guarantee clear answers about disease status through conventional testing. To address this gap, Ibsen and his team investigated whether blood proteins could serve as reliable biomarkers—measurable substances indicating health or disease states.

Study analyzes patient samples

The researchers examined 264 blood and tissue samples collected from Rikshospitalet between 2018 and 2024. These samples included material from people with coeliac disease taken before they began treatment and after one year on a gluten-free diet, as well as samples from individuals without the condition. All participants had consented to the use of their biological data for research purposes.

Using proteomics, a technique enabling the simultaneous analysis of numerous proteins, the team identified 24 proteins associated with coeliac disease. Nine of these were specifically linked to the severity of intestinal damage, potentially indicating how far the disease has advanced. Ibsen stated that distinct differences were observed between untreated patients and healthy controls for many of these proteins.

Residual inflammation persists

Data showed that individuals with untreated coeliac disease exhibited the highest levels of inflammatory proteins, while healthy subjects had the lowest. Significant shifts in protein levels were also detected before and after treatment, suggesting these markers offer detailed insights into gut healing and ongoing inflammation. However, patients adhering to a gluten-free diet still displayed slightly elevated levels of certain proteins compared to healthy individuals.

“The findings therefore suggest that patients have some inflammation in the gut even when they follow the diet,” Ibsen said. This residual activity highlights the limitations of current monitoring methods, which rely heavily on anti-tTG IgA antibodies and total IgA levels measured via blood tests and gastroscopy.

Complementing existing diagnostic tools

Following diagnosis, general practitioners typically monitor patients using the same antibody-based blood tests. Ibsen explained that this method becomes less informative once treatment begins, noting that research indicates it can be misleading regarding actual gut conditions. “The problem with this blood test is that it simply does not work as well once patients have started treatment with a gluten-free diet,” he said.

The study authors hope that assays based on these newly identified biomarkers will eventually complement, rather than replace, serology—the standard test currently in use. Ibsen emphasized that such tools could provide a more accurate picture of disease development and offer reassuring follow-up options for patients navigating long-term management of coeliac disease.