Dietary rutin supplementation enhances growth performance, intestinal health, and cecal microbiota in broiler chickens.

This study evaluated the effects of rutin supplementation on the growth performance and gut health of broilers. A total of 270 one-day-old Arbor Acres broilers were raised in a 28-day feeding trial. The birds were randomly divided into three groups (6 replicates per treatment, 15 broilers per replicate): CON (basal diet); RUT500 (basal diet + 500 mg/kg rutin); RUT1000 (basal diet + 1000 mg/kg rutin). Compared to the CON group, dietary rutin supplementation significantly improved growth performance, villus height, serum sIgA levels, and catalase (CAT) activity. The RUT500 group showed a significant increase in spleen index (p < 0.05), while the RUT1000 group exhibited significantly higher bursa index, serum IgM levels, serum d-lactic acid (D-LA) levels, and total antioxidant capacity (T-AOC) (p < 0.05). In both RUT500 and RUT1000 groups, mRNA expression of IL-4, IL-6, INF-γ, TNF-α, NF-кB, BAX, Caspase-3, and TLR-4 was significantly downregulated (p < 0.05), whereas BCL-2 and Mucin-2 expression was upregulated (p < 0.05). At the protein level, TLR-4, Caspase-3, and BAX were significantly reduced (p < 0.05), while BCL-2 was increased in rutin-supplemented groups. The RUT1000 group also showed decreased NF-кB and TLR-4 protein expression (p < 0.05). Microbiota analysis revealed that the RUT500 and RUT1000 groups had significantly higher Chao1 and Simpson diversity indices (p < 0.05) compared to CON. Beta diversity differed significantly between CON and RUT1000 (p < 0.05). Rutin supplementation reduced the abundance of Proteobacteria and Erysipelotrichaceae (p < 0.05), while the RUT500 group showed increased Bacteroidaceae and Ruminococcaceae_Ruminococcus compared to CON group. In conclusion, dietary rutin enhanced growth performance and gut health in broilers.