Abstract

Eimeria tenella ( E. tenella ) , a pathogenic protozoan parasite, poses a significant threat to the global poultry industry due to its severe impact on intestinal health and growth performance. Given the limitations of conventional anticoccidial drugs, such as the development of drug resistance and chemical residues, it is imperative to explore natural alternative strategies for effective control. In this study, we evaluated the synergistic anti-coccidial effect of pomegranate peel extract (PPE) and Bacillus subtilis (BS). PPE exhibits antioxidant and anti-inflammatory properties, whereas BS, contributes to maintaining intestinal microbial balance. Broiler chickens were challenged with E. tenella and treated with 400   mg/kg PPE in feed and 400   mg/L BS in drinking water, using diclazuril (DIC) as a positive control. The results demonstrated that the PPE+BS combination significantly alleviated cecal lesions, reduced oocyst it mainly parasitizes on the mucosa of the cecum output and mortality, lowered organ indices, suppressed inflammatory responses, and restored body weight gain. The anti-coccidial index (ACI) reached 163, indicating moderate efficacy. Gut microbiota analysis revealed that PPE+BS restored microbial homeostasis by increasing the abundance of Firmicutes, reducing Escherichia coli and Enterococcus , and restoring Micrococcus to levels comparable to uninfected controls. To further explore the potential of the intestinal probiotics, Lactobacillus salivarius (LS) and Lactobacillus curvatus (LC), isolated and identified from chicken feces, achieved comparable anti-coccidial efficacy when combined with PPE, confirming the role of specific probiotics in the observed synergy. In conclusion, the combination of PPE and BS represents an effective and sustainable strategy for controlling avian coccidiosis, primarily through modulation of the gut microbi