Ultra-Processed Foods Consumption Is Positively Associated with the Clinical Activity of Inflammatory Bowel Diseases: A Cross-Sectional Single-Center Study.

Introduction: Western diet pattern and its food components have been suggested to impact inflammatory bowel diseases (IBDs) clinical course. However, the importance of food processing level is uncertain. We aimed to evaluate whether the intake of foods with varying processing levels is associated with disease activity in IBD patients.

Methods: This cross-sectional study was performed at a tertiary center between August 2019 and June 2022. Consecutive adult IBD patients were recruited. Clinical disease activity was defined using HBI (Crohn's disease) and SCCAI (ulcerative colitis). Dietary intake was assessed using a food frequency questionnaire (FFQ) and a dedicated validated processed food questionnaire (PFQ) that categorizes dietary intake into three groups of processed food levels: unprocessed/minimally processed, processed, and ultra-processed. Adjusted odds ratios for active disease were determined using a multivariable logistic regression.

Results: A total of 242 IBD patients (62.8% Crohn's disease patients) were enrolled, of whom 73.1% were in clinical remission. A higher (upper tertile vs. lowest tertile) unprocessed/minimally processed foods consumption was negatively associated with active disease (OR = 0.38, 95% CI: 0.14-0.99), while high consumption of ultra-processed foods (UPFs) was positively associated with clinically active disease (OR = 3.82, 95% CI: 1.49-9.8). Consumption of UPF groups, almost invariably, was positively associated with clinically active disease, while consumption of the ultra-processed meats group had the strongest association (OR = 4.45, 95% CI: 2.07-9.79).

Conclusion: Higher consumption of UPFs is positively associated with clinically active IBD, while higher consumption of unprocessed/minimally processed foods may be protective. Prospective studies are needed to confirm these associations.