Dietary Artemisia annua leaf powder modulates intestinal response and cecal microbiota of broiler chickens during peak Eimeria infection

A study was conducted to evaluate the effects of dietary Artemisia annua leaf powder supplementation on growth performance, intestinal health, and cecal microbiota composition in broiler chickens challenged with mixed Eimeria species. A total of 390 one-day-old Cobb 500 chicks were allocated to 5 treatments with 6 replicates of 13 birds each: a non-challenged control (NC), a challenged control (CC), and three challenged groups supplemented with A. annua leaf powder at 0.15, 0.30, and 0.45 %. Birds in the challenged treatments were orally inoculated on day 14 with 10,000 E. maxima, 10,000 E. tenella, and 25,000 E. acervulina oocysts. Growth performance was evaluated from 0 to 6 dpi, and lesion scores, oocyst shedding, intestinal morphology, gene expression, and cecal microbiota were evaluated at 6 dpi. Eimeria challenge significantly reduced body weight gain and feed intake (P < 0.001) and increased feed conversion ratio from 0 to 6 dpi (P = 0.003). Supplementation with 0.15 % A. annua improved body weight gain and feed intake (P < 0.05), whereas higher inclusion levels showed no additional benefit. Intestinal permeability and lesion scores increased in challenged birds (P < 0.001), with a tendency for reduced cecal lesions at higher A. annua levels (linear, P = 0.06). Tight junction gene expression was largely unaffected; however, MUC-2 mRNA expression was significantly downregulated in challenged groups (P < 0.001) and increased linearly with increasing dietary Artemisia annua level (P = 0.02). Cytokine analysis showed reduced IL-1β expression in the 0.15 % A. annua group compared with CC (P = 0.002). Microbial analysis showed no significant differences in α-diversity, whereas β-diversity differed among treatments (PERMANOVA unweighted P = 0.001; weighted P = 0.004). A. annua was associated with increased Bacteroidota and reduced Pseudomonadota abundance, while being correlated with decreased Enterobacteriaceae and enrichment of fermentative taxa such as Lachnospiraceae, Rikenellaceae, Oscillospiraceae, and Bacteroidaceae. Dietary A. annua partially reduced Eimeria-induced intestinal damage and improved gut microbial balance.