Kun Xu, Huricha Bao, Jianping Tao, Nianyu Xue
Avian coccidiosis is an intestinal disease caused by several different Eimeria spp. that impair the host's intestinal system, resulting in poor nutrition absorption, reduced growth, and often death. Increasing evidence from recent studies indicates that Eimeria infection disrupts epithelial integrity and reshapes the intestinal microbial ecosystem. Probiotics can enhance poultry productivity and gut health by modulating the microbiome, with certain probiotics demonstrating anticoccidial properties. A detailed understanding of Eimeria-induced dysbiosis, barrier injury, mucosal inflammation, secondary bacterial risk, and probiotic-mediated control is necessary for the effective application of probiotics in commercial practice and for developing logical strategies to control coccidiosis in the post-antibiotic era. This review differs from general coccidiosis or probiotic reviews by integrating evidence across five linked dimensions: Eimeria species, intestinal site, time after infection, probiotic strain or function, and production translation. It summarizes the current understanding of Eimeria-driven gut microbiota dysbiosis and probiotic-based interventions for chicken coccidiosis, with a focus on intestinal site specificity, temporal microbial patterns, microbial metabolism, host-microbiota interactions, and practical implications for poultry production. Future research should move from correlation-based microbiota profiling toward strain-resolved, mechanism-oriented, and production-relevant evaluation.