Salmonella Typhimurium infection disrupts but continuous feeding of Bacillus based probiotic restores gut microbiota in infected hens

Abstract

Abstract Background The gut microbiota plays an important role in the colonisation resistance and invasion of pathogens. Salmonella Typhimurium has the potential to establish a niche by displacing the microbiota in the chicken gut causing continuous faecal shedding that can result in contaminated eggs or egg products. In the current study, we investigated the dynamics of gut microbiota in laying chickens during Salmonella Typhimurium infection. The optimisation of the use of an infeed probiotic supplement for restoration of gut microbial balance and reduction of Salmonella Typhimurium load was also investigated. Results Salmonella infection caused dysbiosis by decreasing (FDR 0.05) by Salmonella challenge and the butyrate level was increased by the continuous feeding of the probiotic. Probiotic supplementation in Salmonella challenged chickens resulted in higher level of propionate. Continuous probiotic supplementation decreased (P < 0.05) the overall mean load of Salmonella in faeces and had a significant effect on Salmonella load reduction in internal organs. Conclusions Salmonella challenge negatively impacts the diversity and abundance of many gut microbial genera involved in important functions such as organic acid and vitamin production. Strategic feeding of a Bacillus based probiotic helps in restoring many of the microbial genera displaced by Salmonella Typhimurium challenge.

Keywords

• 16S rRNA sequencing
• Chicken gut microbiota
• Gut metabolites
• Salmonella Typhimurium
• Strategic feeding of probiotic