Modulation of poultry gut microbiota by phytogenic blend and high concentrations of casein in a validated in vitro cecal chicken alimentary tract model

Phytogenic blends (PB) are composed of various bioactive plant-derived compounds that are used as growth promotors for livestock. Feed additives based on PBs have beneficial effects on farm animals production performance, health, and overall well-being, as well as positive modulating effect on gut microbiota. In this study, we used a validated in vitro cecal Chicken ALIMEntary tRact mOdel (CALIMERO-2) to evaluate the effects of PB, alone or in combination with casein (control), on poultry cecal microbiota. Supplementation with PB significantly increased the abundance of bacteria associated with energy metabolism (Monoglobus) and growth performance in poultry (Lachnospiraceae UCG-010). PB also decreased the abundance of opportunistic pathogens (Escherichia-Shigella), and most importantly did not promote other opportunistic pathogens, which indicates the safety of this blend for poultry. In conclusion, the results of this study show promising perspectives on using studied PB as a feed additive for poultry, although this data should be proven in further in vivo studies.