Dietary supplementation of Radix Isatidis polysaccharides improves meat quality in broilers by regulating lipid metabolism, antioxidant defense, and the gut-muscle axis.

This research assessed the impact of Radix Isatidis polysaccharides (RIPS) supplementation on the growth, meat quality, lipid metabolism, and gut microbiota of broiler chickens. A total of 320 AA broilers were separated into four groups and given either a basic diet or diets with 250, 500, or 1000 mg/kg RIPS for 42 days. We employed various multi-omics approaches, including serum biochemistry, lipidomics, transcriptomics, and 16S rRNA sequencing, to investigate the underlying mechanisms. The results indicated that 1000 mg/kg RIPS markedly enhanced meat color, elevated ω-3 and ω-6 polyunsaturated fatty acids, and augmented antioxidant activity in breast muscle. In the 500 mg/kg and 1000 mg/kg groups, alanine aminotransferase (ALT) activity was significantly decreased, and triglyceride (TG) levels were significantly reduced in the 1000 mg/kg group. Lipidomic analysis revealed that in the 1000 mg/kg group, the accumulation of triglycerides and ceramides in the chicken breast was lower, indicating an optimization of lipid metabolism. Transcriptomic analysis showed that in the ileum, the expression of FABP1 and APOA1 genes was significantly upregulated in the 1000 mg/kg group, suggesting improved fatty acid transport and cholesterol metabolism. RIPS also significantly improved the gut microbiota, particularly increasing the abundance of g__Actinomarinales and p__DTB120 in the 1000 mg/kg group, which were positively correlated with antioxidant capacity and meat quality. In summary, RIPS regulates lipid metabolism and antioxidant defense through the "gut-muscle axis," leading to significant improvements in both meat quality and health in broiler chickens. This study emphasizes the potential of plant polysaccharides in animal nutrition and suggests 1000 mg/kg RIPS as an appropriate supplementation amount.