Oats in a strictly gluten-free diet is associated with decreased gluten intake and increased serum bilirubin

SummaryBackground and aimsTo investigate clinical, nutritional, and laboratory parameters during oats challenge and to cross-sectionally examine the levels of plasma bilirubin in a cohort of coeliac disease patients.MethodsIntestinal biopsies, gastrointestinal symptom registration, standard blood tests, anthropometry, weighed food records, and calculations of nutrients and gluten were performed in 19 patients before and after oats challenge (50 g/day). To further investigate bilirubin levels, blood samples were analysed in 136 patients (82 oats consumers) and 141 healthy controls.ResultsThree of 19 patients developed gastrointestinal symptoms during oats challenge. Compliance with gluten-free diet was good. Dietary fibre intake increased after oats inclusion (p < 0.024) and met recommended levels. With three exceptions, calculated gluten intake remained within the proposed safe level and decreased after oats intake. Total P-bilirubin increased after oats challenge (p < 0.003). In the cohort study a tendency of higher bilirubin levels was seen among oats consumers (17 g/day).ConclusionsGluten-free oats were associated with recommended levels of dietary fibre, and calculated gluten intake was reduced by more than 50%. Gluten-free oats induced higher levels of the anti-oxidant bilirubin in treated coeliac disease patients. This may have positive health implications.