Effects of Multi-Strain Probiotics Combined with Gardeniae fructus on Intestinal Microbiota, Metabolites, and Morphology in Broilers

This study was conducted to investigate the effects of a multi-strain probiotic combined with Gardeniae fructus on the growth performance, intestinal microbiota composition and metabolites, and intestinal morphology of broiler chickens. The dietary treatments included the basal diet without any antimicrobials (C), the basal diet supplemented with 10 ppm avilamycin (A), the basal diet supplemented with 0.1% multi-strain probiotics powder containing Lactobacillus acidophilus LAP5, L. fermentum P2, L. casei L21, and Pediococcus acidophilus LS (1×10⁷ CFU/g) (P), and the basal diet supplemented with a mixture of 0.1% multi-strain probiotics and 0.05% herbal medicine G. fructus (PH). The results showed no significant differences in growth performance across all groups. A denaturing gradient gel electrophoresis analysis indicated that the groups PH, P, and A exhibited an increase in the similarity coefficients of their intestinal microbial populations. The real-time polymerase chain reaction (PCR) analysis showed that the relative concentrations of Firmicutes and Lactobacillus in the cecum and Bifidobacterium spp. in the ileum were higher in the groups PH, P, and A than in group C, and the diet supplemented with multi-strain probiotics combined with G. fructus decreased the concentrations of cecal Escherichia spp. and Clostridium perfringens. The broilers fed with multi-strain probiotics combined with G. fructus showed a significant increase (P<0.05) in the cecal short-chain fatty acids (total SCFA, acetic acid, and butyric acid) compared to the other groups. The treatment with antibiotics, multi-strain probiotics, or multi-strain probiotics combined with G. fructus increased the villus height/crypt depth ratio in the ileum of broilers. In conclusion, the supplementation of multi-strain probiotics combined with G. fructus was beneficial to the intestinal microflora composition, metabolites, and morphology in broilers.