Polystyrene micro- and nanoplastics in a colitis mouse model – effects on biodistribution, macrophage polarization, and gut microbiome

Verena Kopatz Verena Kopatz Ulrike Resch Ulrike Resch Kristina Draganic Kristina Draganic Angela Horvath Angela Horvath Janette Pfneissl Janette Pfneissl Julijan Kabiljo Julijan Kabiljo Bernadette Mödl Bernadette Mödl Gerald Timelthaler Gerald Timelthaler Julia Wallner Julia Wallner Zeynab Mirzaei Zeynab Mirzaei Saule Beratlyte Saule Beratlyte Michaela Schlederer Michaela Schlederer Stefan Sarbu Stefan Sarbu Simina Laslau Simina Laslau Oldamur Hollóczki Oldamur Hollóczki Martin Raigel Martin Raigel Elisabeth S. Gruber Elisabeth S. Gruber Joachim Widder Joachim Widder Iris Kufferath Iris Kufferath Marion Pollheimer Marion Pollheimer Wolfgang Wadsak Wolfgang Wadsak George Sarau George Sarau Silke Christiansen Silke Christiansen Nikola Zlatkov Kolev Nikola Zlatkov Kolev Marcus Krueger Marcus Krueger Robert Eferl Robert Eferl Gerda Egger Gerda Egger Vanessa Stadlbauer Vanessa Stadlbauer Verena Pichler Verena Pichler Lukas Kenner Lukas Kenner Polystyrene micro- and nanoplastics in a colitis mouse model – effects on biodistribution, macrophage polarization, and gut microbiome Springer 2026 The increasing prevalence of inflammatory bowel disease (IBD) and rising pollution from micro- and nanoplastic (MNP) particles has prompted investigations on their potential interconnection. To elucidate the complex relationship between IBD and exposure to MNPs, we induced colitis in mice using dextran sodium sulfate (DSS) and orally administered a mixture of polystyrene (PS) MNPs (diameter 10, 1, and 0.29 µm). These particles enabled a detailed examination of MNP biodistribution, innate immune cell response and gut microbiome alterations under inflammatory conditions. Specifically, the nanosized PS particles predominantly accumulated in the bloodstream and excretory organs, with enhanced accumulation in the inflamed gut/colon. Proteomic analysis of the colon revealed alterations in molecular pathways related to protein transport, metabolism, and immune responses. Specifically, we found macrophage proteome signatures with pro-inflammatory polarization, highlighting the intricate effects of MNPs on inflammation and immune cell behavior. Moreover, MNPs significantly disrupted the gut microbiome, reducing microbial diversity and shifting bacterial populations towards pro-inflammatory and potentially pathogenic species. These changes suggest that MNP exposure could exacerbate colitis through complex interactions involving MNPs, immune responses, and microbial dynamics. The widespread presence of MNPs underscores the urgent need for comprehensive strategies to address MNP pollution, its implications for disease, and potential impacts on public health. PDFDocument eng 2026-07-23T09:46:17.216728398Z 2026 Micro- and Nanoplastic Polystyrene Colitis Mouse Model Proteomics Gut Microbiome 13398427 b application/pdf http://creativecommons.org/licenses/by/4.0/