Effects of Yupingfeng Polysaccharides as Feed Supplement on Immune Function and Intestinal Microbiome in Chickens

The health of chicks is closely related to their productivity. Yupingfeng polysaccharide (YPF-P) is a kind of water-soluble polysaccharide extracted from Yupingfeng powder; it has high pharmacological activity and can be used as a potential substitute for antibiotics to improve the health of chicks. This study aimed to investigate the effects of YPF-P on immune performance, the duodenum, and the cecal microflora of chicks. All chickens (4224) were randomly distributed into four groups (eight replicas/group, 132 hens/replica). The control group was fed a basal diet (0 g/kg YPF-P), while the experimental groups were fed basal diets supplemented with 1, 2, or 4 g/kg YPF-P. The results showed that YPF-P significantly increased the thymus index (p < 0.05). The content of total antioxidant capacity (T-AOC), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), immunoglobulin A (IgA), and IgG and immunoglobulin M (IgM) was upregulated in the serum by YPF-P (p < 0.05). YPF-P decreased the content of malondialdehyde (MDA) (p < 0.05). Further, 16S rRNA sequencing showed that 2 g/kg YPF-P modulated the predominant duodenum and cecal microbial community structure, which increased the number of Faecalibacterium, Megamonas, Bacteroides, Alistipes, NK4A214_group, and Enterococcus. In conclusion, YPF-P ameliorated the growth performance of chicks by regulating serum immune and antioxidant balance, as well as the intestinal microbiota.