Inclusion of Lactobacillus salivarius strain revealed a positive effect on improving growth performance, fecal microbiota and immunological responses in chicken

Probiotics are defined as live microorganisms that when administered in an appropriate amount, provide health benefits to the host. This study aimed to evaluate the effect of the oral administration of Lactobacillus salivarius (L. salivarius) on growth performance, immunological responses, fecal microbial flora and intestinal mucosal morphology in chickens. Chickens were fed with 10⁹ colony-forming units (CFUs) of wild-type (WT) L. salivarius or phosphate-buffered saline (PBS) for 5 weeks. Chickens body weight was significantly increased by administration of L. salivarius groups compared than control group. The microbial taxonomy in the small intestine and cecum was identified via the chicken feces sample. A total of 286,331 bacterial species were obtained from the chicken fecal samples in overall experimental group. From these, 145,012 bacterial species were obtained from oral administration of L. salivarius treatment group, while 141,319 bacterial species were obtained from control group. Almost 98% of all 16S rRNA sequences from the chicken fecal sample of the two groups were classified into known phyla. Firmicutes, Cyanobacteria, Proteobacteria, Bacteroidetes and Actinobacteria were highly abundant in both groups. Compared with the control birds, the chickens orally administered L. salivarius showed no significant differences in villus length and crypt length. Serum concentrations of the cytokines IL-8, TNF-α, IFN-γ, and IL-4 were markedly reduced in the L. salivarius group. In summary, our findings reveal that L. salivarius can act as a potential probiotic to improve performance and overall gut health in of chickens.