<b><i>Entamoeba muris as a Model Organism for an Amoebic Colitis-Like Pathology Characterized by T-cell-Associated Colonization</i></b>

<i>Entamoeba (E.) histolytica</i> is a major global health concern as the causative agent of amoebic colitis, yet research is hindered by the lack of an ideal animal model. While <i>E. muris </i>has been traditionally considered non-pathogenic, our study demonstrates that it induces a colitis-like pathology in BALB/c mice, making it a promising model for studying <i>E. histolytica </i>infection. Using a fecal-oral infection route, we confirmed successful <i>E. muris</i> colonization, leading to colonic inflammation characterized by early CD4+ T-cell infiltration and FOXP3+ regulatory T-cell recruitment. We further demonstrate that T-cell immunity is essential for <i>E. muris</i> colonization, as T-cell-depleted BALB/c mice and T-cell-deficient BALB/c nude mice failed to support persistent infection. Additionally, infection disrupts epithelial homeostasis, impairing goblet cell generation, and induces significant shifts in gut microbiota composition, notably reducing beneficial <i>Firmicutes</i> species. Collectively, these findings demonstrate that <i>E. muris </i>infection induces inflammation and microbiota alterations, mirroring critical aspects of amoebic colitis, reinforcing its value as a model for studying <i>E. histolytica </i>pathogenesis and host–parasite interactions.<br>1~7 : No infection group<br><br>11 ~20 : <i>E.muris</i> infection group