Entamoeba muris as a Model Organism for an Amoebic Colitis-Like Pathology Characterized by T-cell-Associated Colonization

Entamoeba (E.) histolytica 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 E. muris 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 E. histolytica infection. Using a fecal-oral infection route, we confirmed successful E. muris 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 E. muris 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 Firmicutes species. Collectively, these findings demonstrate that E. muris infection induces inflammation and microbiota alterations, mirroring critical aspects of amoebic colitis, reinforcing its value as a model for studying E. histolytica pathogenesis and host–parasite interactions.1~7 : No infection group11 ~20 : E.muris infection group