Probiotic Paenibacillus polymyxa 10 and Lactobacillus plantarum 16 enhance growth performance of broilers by improving the intestinal health

With the eve r-growing strict prohibitions on antibiotic growth promoters(AGP) in animal production,in-feed probiotics are becoming attractive alternatives to antibiotics in the poultry industry.To investigate the effects of Paenibacillus polymyxa 10 and Lactobacillus plantaru m 16 on the growth performance and intestinal health of broilers,540 male Cobb 500 broilers of 1 d old were randomly divided into 3 groups with 6 replicates pergroup and 30 chicks per replicate.Broilers were fed with either a basal diet or basal diets supplemented with1 × 10～8 colony-forming units(CFU)/kg P. polymyxa 10(BSC10) or L.plantarum 16(Lac16) for 42 d.Results showed that Lac16 treatment improved(P<0.05) the growth perfo rmance(body weight and feed conversion)of broilers at the starter phase,while BSC10 treatment slightly improved(P>0.05) the growth performance of the starter phase broilers.The increased villus height(P<0.05) at d 14,21 and 42 and villus height to crypt depth ratio(P<0.05) at d 14 and 21 were observed in the ileum of the 2 probiotic groups.Besides,transmission electron microscopy results showed that the 2 probiotics enhanced the intestinal epithelial barrier.Both probiotic treatments up-regulated(P<0.05) the mRNA expression of fatty acid binding protein 1(FABP1) and sodium-dependent glucose transporters-1(SGLT-1) in the ileal mucosa of broilers at d 21.In addition,BSC10 and Lac16 treatments significantly(P<0.05) increased the relative abundance of short-chain fatty acidsproducing bacteria,such as Butyricicoccus pullicaecorum,Faecalibacterium prausnitzii,Lachnospira and Coprococcu,and significantly(P<0.05) decreased the relative abundance of enteric pathogens(Escherichia coli,Bacteroides fragilis and Shigella sonnei).Furthermore,the 2 probiotic treatments also increased the positive connection among the intestinal microbes and the carbohydrate metabolism-related pathways of the intestinal bacteria(P<0.05),with decreasing(P<0.05) nucleotides biosynthesis-related pathways of the intestinal bacteria.Overall,these results suggest that the 2 probiotics,especially Lac16,have a potential beneficial effect on the growth performance and intestinal health of starter phase broilers.