MOY 02 Transcutaneous Fluorescence Sensing of Gastrointestinal Permeability in Humans: Cross-Cohort Validation of a Novel Fluoroscopic Device in Health, Disease, and Challenge Models
Pratik Ramkumar, Qian Chen, Nilanjan Mandal, Jonathan Gan, Elena Montfort-Sanchez, Alex ThompsonAbstract
Aims
Intestinal permeability is increasingly recognised as a feature of inflammatory and functional gastrointestinal disorders1,2, both of which present overlapping symptoms3 and diagnostic ambiguity4, contributing to disease burden5,6. Existing diagnostics are limited by heterogeneity and confounding from gastric motility7,8. To address these constraints, we developed Transcutaneous Fluorescence Spectroscopy (TFS), a non-invasive method that uses oral fluorescein to dynamically quantify intestinal permeability9,10. This study evaluated the discriminatory performance of TFS-derived biomarkers across functional and inflammatory disease states.
Method
A prospective single-centre study enrolled 66 participants: healthy controls (n=8, pre/post-indomethacin), IBS patients (n=21, pre/post low-FODMAP diet), and Crohn’s disease (CD) patients (n=36) stratified by activity. TFS measurements were collected for 180 minutes following fluorescein ingestion. Fluorescence–time curves were processed with a Savitzky-Golay filter before extracting peak intensity, time-to-peak, and the area under the fluorescence curve (AUC). A Random Forest classifier was trained on curve profiles to classify disease states.
Results
CD patients demonstrated higher peak intensity than both IBS (p<0.0001, r=0.68) and controls (p<0.0001, r=0.50), with IBS participants showing lower peak intensity compared to controls (p<0.0001, r=0.11). CD showed elevated AUC compared with IBS (p<0.0001, r=0.77) and controls (p-0.0078, r=0.39). IBS patients also demonstrated lower AUC compared to controls (p=0.0191, r=0.38). Classification accuracy reached 86% for CD vs IBS,80.6% for IBS vs controls, and 66% for 3-class classification. No significant pre/post-FODMAP differences were detected.
Conclusions
TFS demonstrates promise as a non-invasive tool for distinguishing gastrointestinal disorders. With broader multi-centre validation and longitudinal assessment, TFS may support personalised treatment approaches and facilitate non-invasive disease stratification.