Protective role of Lactobacillus plantarum in Eimeria tenella infection: Impact on hematological, inflammatory, and apoptotic gene responses

Coccidiosis, a major parasitic disease in poultry, causes substantial economic losses worldwide. The rise of drug-resistant Eimeria strains has intensified the need for alternative control measures. This study evaluated the probiotic Lactobacillus plantarum (L. plantarum) as a dietary supplement to protect chickens from Eimeria tenella (E. tenella) infection. We examined its effects on growth performance, disease severity, cecal lesions, oocyst scores, immune response, haematological parameters, and the expression of genes related to inflammation and apoptosis. The levels of pro-inflammatory cytokines (IL-6 and IL-8) and apoptosis-related proteins (Bax, Bcl-2, and caspase-3) were measured by mRNA expression. Probiotic-supplemented groups downregulated the mRNA expression levels of the pro-apoptosis protein Bax. They up-regulated the mRNA expression levels of the anti-apoptosis protein Bcl-2 more than those of the control groups. The findings also showed a statistically higher lymphoproliferative (P < 0.05) response in the probiotics @1.5 × 10⁸ CFU)-supplemented group in feed compared to the control group. The probiotics administered in the feed groups showed reduced oocysts shedding, fewer intestinal lesions, and improved hematological parameters than the control (E. tenella infected, non-treated) group. The research showed that probiotic supplementation without anticoccidial drugs could protect chickens against the adverse effects of E. tenella.