Core gut microbiota in rabbit: opportunities to strengthen the intestinal barrier

The symbiotic relationship between the intestinal microbiota and its host is crucial to the development and functioning of both partners. The microbiota plays a key role in the development and physiology of its host (nutrition, growth, health and cognition). In turn, the host shapes the microbiota, according to factors that are intrinsic or dependent on its environment. However, the definition of an optimal microbiota that maximises ecosystem services (host benefits) has yet not been established. The symbiotic relationship between the microbiota and its host is based on a complex molecular dialogue at the level of the intestinal epithelium and the underlying mucosal immune system. These interactions condition the establishment of an intestinal barrier, limiting colonisation by microbial pathogens and thereby guaranteeing health. In this review, we propose a ‘core’ rabbit microbiota definition through a re-analysis of available opensource data. Based on the association between the abundance of bacterial taxa and host traits, we attempt to identify microbiota key species that would likely be involved in growth performance and health. Then, we describe the components of the intestinal barrier and the host-microbiota interaction mechanisms. Finally, we propose early in life nutritional levers to strengthen this intestinal barrier and thereby enhance the health of young rabbits before weaning.