Saikosaponin inhibits Eimeria tenella infection by modifying the NF-κB pathway and regulating cytokines and the intestinal microbial community.

Eimeria tenella (E. tenella) is an intestinal parasite that not only endangers the health of broiler chickens but may also cause death in severe cases. However, the growing critical problem of drug resistance in E. tenella complicates therapy. Consequently, a more natural and safer technique for treating E. tenella is urgently warranted. Saikosaponin (SS) is a saponin component extracted from the traditional Chinese herb Chaihu that has been demonstrated to treat various diseases. However, little is known regarding the function of SS in E. tenella treatment. In the present investigation, SS lowered the weight loss rate and increased the survival rate of broiler chickens infected with E. tenella. SS inhibited the NF-κB pathway and regulated the gut microbiota structure to inhibit E. tenella-induced inflammatory damage in broiler chickens. In addition, 16S high-throughput sequencing results demonstrated that SS reconstructed the gut microbiota of E. tenella infected broilers, preserving gut microbial balance, increasing the production of total short-chain fatty acids (SCFAs), repairing intestinal villi and intestinal wall integrity, and decreasing inflammatory cell infiltration in the cecum. Overall, these findings show that SS could prevent E. tenella-induced inflammatory damage in broiler chickens by blocking the NF-κ B pathway and regulating the gut microbiota composition.