Differential impact of microplastic polymers on the development of chronic DSS-induced colitis in mice
Year: 2026
Type: conference-paper
Abstract: Inflammatory bowel diseases (IBD) arise from dysregulated immune responses at the intestinal barrier driven by genetic susceptibility and environmental exposures. Microplastics (MPs) are widespread environmental contaminants with potential immunomodulatory effects, yet their role in intestinal inflammation remains poorly defined. We hypothesized that MP exposure exacerbates colitis by reshaping the gut microbiota and disrupting mucosal homeostasis in a polymer- and sizedependentmanner.Eight-week-old male C57BL/6 mice were exposed for four weeks to polyamide (PA), polyvinyl chloride (PVC), or polyethylene terephthalate (PET) MPs (0.5 or 5 μm), administered via drinking water either individually or as a mixture. Chronic colitis was induced using 2% dextran sodium sulfate (DSS) in four 5-day cycles. Disease activity was monitored daily. Endoscopic, histopathological, and intestinal immune analyses were performed at study termination. Gut microbiota composition was assessedlongitudinally throughout DSS exposure.Four-week MP exposure altered gut microbiota composition and diversity in a polymer-specific manner. While PA did not affect DSS-induced colitis, PVC and PET exposure increased disease severity during the first two DSS cycles. Combined exposure to all three polymers markedly exacerbated clinical disease activity during the first DSS cycle, revealing a pronounced early cocktail effect. After four DSS cycles, disease severity and immune profiles were comparable between groups. Ongoing analyses aim to delineate the early inflammatory pathways underlying this transient exacerbation.These findings identify microplastics as environmental modifiers of early intestinal inflammation and highlight a synergistic effect of mixed polymers. This work provides mechanistic insight into how environmental pollution may contribute to IBD pathogenesis.
Source: HAL
Language: English
Subfield: Pollution
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7205885459