Quantifying artificial sweeteners and emulsifiers in Crohn's disease and its relationship with disease activity: the ENIGMA study - a novel and targeted approach

Background: Food additives have been linked to increased Crohn's disease (CD) risk and activity, but their human quantification has not been explored. Objective: We aimed to measure artificial sweeteners and emulsifier polysorbate-80 (P-80) in patients with CD and assess their associations with disease activity. Design: 1461 biosamples from 487 subjects (245 CD and 242 controls) across Australia, Hong Kong and Chinese Mainland were analysed for aspartame, sucralose, saccharin and P-80 levels in stool, urine and serum. CD activity was assessed using Crohn's Disease Activity Index and faecal calprotectin. A generalised linear model (GLM) with P-80 and sweeteners distinguished active CD from inactive CD. Results: Patients with CD had higher sweetener levels compared with controls across cohorts (all p<0.0001). P-80 underwent predominantly hydrolytic and oxidoreductive degradation in CD and controls, respectively, while its native form was undetectable. CD-associated P-80 metabolites positively correlated with urinary sweeteners in patients with CD. In vitro, CD-associated P-80 metabolites increased gut permeability, enabling translocation of sweeteners across the epithelium. Sweeteners and specific CD-associated P-80 metabolites were higher in active CD. The GLM built using sweeteners and P-80 metabolites distinguished active CD from inactive CD, achieving an area under the curve (AUC) of 0.86 in the discovery cohort and average AUC of 0.94 in two independent validation cohorts from Australia and Chinese Mainland. Conclusion: This is the first human study to demonstrate distinct P-80 metabolism in patients with CD compared with controls. Dietary sweeteners and P-80 metabolites showed significant correlations with disease activity, suggesting their potential utility as non-invasive biomarkers for CD activity assessment.