Effect Of AERISCARDOVIA AERIPHILA On Growth Performance,Serum Immune Levels,Antioxidant Capacity,and Gut Microbiota In Broiler Chickens

Aeriscardovia aeriphila,also known as Bifidobacterium aerophilum,was isolated from the caecal contents of pigs and the faeces of cotton-top tamarin.Bifidobacterium species play important roles in preventing intestinal infections,decreasing cholesterol levels,and stimulating the immune system.In this study,we first isolated a strain of bacteria from the duodenal contents of broiler chickens and be identified as A.aeriphila.We then evaluated the effects of A.aeriphila on growth performance,antioxidant functions,immune functions,and gut microbiota in commercial broiler chickens.Chickens were orally gavaged with A.aeriphila(10~9 CFU/m L)for 21 days.The results showed that A.aeriphila treatment significantly increased the average daily gain and reduced the feed conversion ratio(P<0.001).The levels of serum growth hormone(GH)and insulin-like growth factor1(IGF-1)were significantly increased following A.aeriphila treatment(P<0.05).Blood urea nitrogen and aspartate aminotransferase levels were decreased,whereas glucose and creatinine levels increased as a result of A.aeriphila treatment.Furthermore,the levels of serum antioxidant enzymes,including catalase(P<0.01),superoxide dismutase(P<0.001),and glutathione peroxidase(P<0.05),and total antioxidant capacity(P<0.05)were enhanced following A.aeriphila treatment.A.aeriphila treatment significantly increased the levels of serum Ig A(P<0.05),Ig G(P<0.01),Ig M(P<0.05),IL-4(P<0.05),IL-1(P<0.05),and IL-10(P<0.05).The broiler chicks in the A.aeriphila group had higher SIg A levels in the duodenum(P<0.01),jejunum(P<0.001),and cecum(P<0.001)than those in the control group.The relative expression levels of IL-10(P<0.05),IL-4(P<0.001),and NF-k B(P<0.001)m RNA in the mucosa of the intestine(including duodenum,jejunum,and cecum)of chicks were higher in the A.aeriphila group than in the control group.Phylum-level analysis revealed Firmicutes as the main phylum,followed by Bacteroidetes,in both groups.The data also confirmed the presence of Terrabacteria,which includes Actinobacteria,Bifidobacteriaceae and Aeriscardovia.In conclusion,oral administration of A.aeriphila could improve the growth performance,serum antioxidant capacity,immune modulation,and gut health of broilers.Our findings may provide important information for the application of A.aeriphila in poultry production.