Habitual dietary fibre and prebiotic intake is inadequate in patients with inflammatory bowel disease: findings from a multicentre cross-sectional study

Background: Recommendations for dietary fibre intake in patients with inflammatory bowel disease are highly variable. Despite the potential benefits of prebiotic fibres on the gut microbiome, many patients with inflammatory bowel disease follow a low fibre diet. The present study comprehensively evaluated intakes of total and prebiotic fibres in patients with inflammatory bowel disease, aiming to determine the adequacy of fibre intake and factors that may influence intake.

Methods: Outpatients with a formal diagnosis of inflammatory bowel disease were recruited to this multicentre cross-sectional study. Habitual dietary fibre intake including prebiotic fibre types was measured using a validated comprehensive nutrition assessment questionnaire. Adequacy of total fibre intake was compared with Australian Nutrient Reference Values. Multiple linear regressions were performed to determine factors influencing fibre intake.

Results: Of 92 participants, 52% had Crohn's disease, 51% were male and the mean age was 40 years. Overall, only 38% of the cohort consumed adequate total fibre (median 24 g day^-1 , interquartile range 18.5-32.9 g day^-1 ). Adequate fibre consumption was significantly less common in males than females (21.3% versus 55.6%, P = 0.002). Resistant starch intake (median 2.9 g day^-1 , interquartile range 2.1-4.8 g day^-1 ) was significantly less than the proposed recommendations (20 g day^-1 ). Disease-related factors such as phenotype and disease activity were not found to influence fibre intake.

Conclusions: Patients with inflammatory bowel disease habitually consume inadequate fibre, particularly prebiotic fibre resistant starch. The potential deleterious effects of low prebiotic intake on the gut microbiome and disease-related outcomes in inflammatory bowel disease are unknown and warrant further research.