IDDF2024-ABS-0251 Analysis of microplastics in human ileum and mesenteric fat reveals a correlation between microplastics and crohn’s disease associated intestinal fibrosis

<h3>Background</h3> Suffering from Crohn’s disease (CD) increases susceptibility to environmental exposures. However, no study has investigated the presence of microplastics (MPs) in paired ileal segments-mesenteric adipose tissue of CD patients or the exposure sources. Therefore, we aim to assess MPs exposure in paired involved and adjacent uninvolved ileal segments (iIleum and uIleum, respectively) with attached creeping fat (CF) and adjacent uninvolved mesenteric adipose tissue (CD-MAT) samples and evaluate the potential sources of pre-crohn’s disease exposure to MPs. <h3>Methods</h3> We recruited 16 pairs of ileal segments-mesenteric adipose tissue from ten CD patients (IDDF2024-ABS-0251 Table 1). Two questionnaires were used to determine the origin of exposure. Sample analysis was conducted using an Agilent 8700 laser infrared imaging spectrometer. <h3>Results</h3> We identified twelve types of MPs, with Chlorinated polyethylene (CPE-36.00%), Acrylate copolymer (ACR-24.16%), Fluororubber (49.96%) and Polyethylene (PE-40.60%) being dominant in each group (IDDF2024-ABS-0251 Figure 1. Relative frequencies of different types of MPs and the correlation between MP concentrations and intestinal fibrosis/inflammation scores in CD patients (A), IDDF2024-ABS-0251 Figure 2. LDIR spectrogram and morphologies of typical MPS, IDDF2024-ABS-0251 Table 2). In CF, a dramatic expansion of Polyurethane (PU) and ACR and a shrinkage of CPE and Fluororubber were consistent with the predominant change in fibrotic intestines. More than half of the MPs discovered measured between 0-50 μm, but each group displayed different size distributions (IDDF2024-ABS-0251-Figure 3. Different shapes and sizes of MPS detected in CD patients (A)). We performed correlation analysis and observed a statistically significant correlation between the concentration of MPs and the severity of ileal fibrosis (IDDF2024-ABS-0251 Figure 1. Relative frequencies of different types of MPs and the correlation between MP concentrations and intestinal fibrosis/inflammation scores in CD patients (B)). The quantity of fragmented microplastics is significantly higher in the iIleum compared to the uIleum, a result contrasting with the quantity observed in both CF and CD-MAT (IDDF2024-ABS-0251-Figure 3. Different shapes and sizes of MPS detected in CD patients (C-E)). <h3>Conclusions</h3> Our study demonstrated compelling evidence that both the intestine and adjacent MAT of CD patients are contaminated with MPs. MPs exposure is positively correlated with the severity of fibrosis. MPs accumulate in the fibrotic intestine and CF, potentially influencing fibrosis and the generation of CF.