People with celiac disease are abnormally sensitive to gluten, a protein that is found in wheat, barley, and rye. This chronic condition is an autoimmune disorder in which the immune system begins to abnormally attack the gut and cause inflammation, which leads to many symptoms that can include bloating, constipation, nausea, abdominal pain, or other issues. Celiac patients may also have difficulty absorbing nutrients from their diet, which can lead to a host of other problems. Right now, the only way to treat the disease is to completely stop consuming gluten, and scientists are still learning about what causes it. Celiac disease usually has to be diagnosed with an intestinal biopsy or blood test.
Scientists have now used magnetic resonance imaging (MRI) to learn more about what happens in the guts of celiac patients who stop consuming gluten. This is particularly important, because researchers are still learning about how celiac disease influences gut physiology, and how gluten-free diets may change that. The findings have been reported in Clinical Gastroenterology and Hepatology.
The investigators recruited 36 recently diagnosed celiac patients and 36 unaffected individuals for this study. MRIs were obtained of everyone's guts, and blood and stool samples were collected at that time. Celiac patients then consumed a gluten-free diet for a year, and then returned for another MRI and sample collection. The unaffected volunteers did the same, but without following a special diet.
The MRIs showed that celiac patients carried more fluid in their small bowels, and food moved through their bowels more slowly compared to unaffected individuals. The celiac patients also carried higher levels of gut bacteria that have been linked to negative health outcomes, such as E coli, at the start of the study.
After their gluten-free year, the MRI showed that celiac patients had less water in their bowels, and improved gut transit. Patients also reported symptom relief. Their gut microbiomes had shifted too, but they were not necessarily more like those of healthy controls. Instead, some of the more beneficial microbes, like Bifidobacteria, had been reduced. These bugs also consume wheat and starch molecules, however, so the diet seems to have lessened their numbers.
"It was particularly interesting to see how the imaging results on gut function correlated with changes in the bugs in the colon microbiota," said senior study author Professor Luca Marciani of the University of Nottingham. "The findings increase our understanding of gut function and physiology in celiac disease and open the possibility of developing prebiotic treatments to reverse the negative impact of the gluten-free diet on the microbiome."
Sources: University of Nottingham, Clinical Gastroenterology and Hepatology (via bioxRiv)
