The research activities of the group of Prof. Van Immerseel focus on host-microbiota interactions in various animal species, with focus on poultry. The general research strategy is to study the interactions between the bacteria and the host and use the generated new insights to develop prevention strategies to reduce intestinal disease. There are several objectives in the group of Prof. Van Immerseel, being: A) to understand the molecular mechanisms used by pathogens to colonize the intestinal tract and internal organs, and cause disease, with a main focus on Salmonella Enteritidis and Clostridium perfringens in poultry, and Enterococcus cecorum in broiler chickens ; B) to understand microbiota-host interactions that drive gut health and develop diagnostics and control measures (vaccines, nutritional interventions) against intestinal diseases, based on knowledge of disease pathogenesis and host-microbiota interactions.