I’m the Guest Editor of this issue. In recent times, the term ‘gut health’ has become increasingly popular as a state of physical well-being in the absence of gastrointestinal complaints. There is clear evidence that the gastrointestinal tract function goes further than feed processing. In fact, the gut has an impact on general health by ensuring digestion and absorption of nutrients, minerals and fluids; by induction of mucosal and systemic tolerance; by defence of the host against biological and other pathogens; and by signalling from the periphery to the brain. For this reason, in veterinary medicine gut health can be considered a synonymous of animal health and can offer a new approach to preventive medicine. Gut health depends on the maintenance of a delicate balance between the host, the gut mucosal barrier/microbiota, the diet and the environment in which the animal lives. Original research papers and reviews that address different strategies (nutritional, environmental or clinical strategies) to improve and maintain the different components of gut health (e.g. intestinal morphology, microbiota, mucins, immune responses/cytokines expression) in food-producing, companion animals and animal models are welcome. The submission deadline is 31 December 2021 If you want to know other details, please feel free to contact me. Regards The guest Editor Prof.ssa Maria Teresa Capucchio