Dietary Patterns and Fibre Intake Are Associated with Disease Activity in Australian Adults with Inflammatory Bowel Disease: An Exploratory Dietary Pattern Analysis.

Background: Few studies have explored the relationship between habitual dietary patterns and disease activity in people with Inflammatory Bowel Disease (IBD). This cross-sectional study explored the association between dietary patterns and clinical and objective markers of inflammation in adults from the Australian IBD Microbiome Study.
Methods: Dietary patterns were derived using principal component analysis (PCA) of baseline food frequency questionnaire data. Food intake was quantified using 3-day food record data. Associations between dietary intake and both clinical disease activity index (CDAI) and faecal calprotectin (FCP) were analysed.
Results: Participants included 412 adults (IBD = 223, Healthy controls (HC) = 189). Both cohorts consumed poor-quality diets with inadequate servings of most food groups compared to Australian reference standards. IBD participants without FCP inflammation had significantly higher fibre intake than those with moderate FCP. In the Crohn's Disease group, high adherence to 'High plant diversity' and 'Meat eaters' dietary patterns were associated with increased CDAI and FCP, respectively. In the combined IBD cohort, high adherence to a 'Vegan-style' dietary pattern was associated with increased FCP.
Conclusions: There is a need for dietary modifications among Australian adults, both with and without IBD, to improve dietary fibre intake and adherence to dietary guidelines. Dietary patterns characterised by a high intake of plant foods or meat products were both positively associated with indicators of active IBD. It is possible that some participants with active IBD were modifying their diet to try to manage their disease and reduce symptoms, contributing to the association between healthier dietary patterns and active disease. Further clinical and longitudinal studies are needed to expand upon the findings. This study offers a unique contribution by utilising FCP as an objective marker of intestinal inflammation and applying dietary pattern analysis to investigate the relationship between diet and inflammatory markers.