Functional feed additive for gut integrity and protection against the intestinal myxosporean endoparasite Enteromyxum leei

Panos G. Kalatzis, Maria Mercè Isern-Subich, Waldo G. Nuez-Ortín, Adisseo

The importance of gut in fish health and performance

A healthy alimentary canal is a fundamental element for the optimal growth and performance of all cultured fish. Apart from nutrient absorption and digestion, which are its main functions, the gut plays also a major role in sustaining fish health (Kristen et al., 2012; Tarnecki et al., 2017). However, there are several, both non-infectious and infectious factors, that may cause imbalance among the major components of the gut: microbiota, epithelium and intraepithelial leukocytes. The amount of scientific research on gut microbiota has been growing exponentially over the past few years (Egerton et al., 2018; Bozzi et al., 2021), however, the complexity of gut microbiome and the potential interventions that may lead to better fish health and performance has only scratched the surface (Montalban et al., 2015). The clinical picture of such an imbalanced gut is called enteritis and occurs in the form of generalized intestinal inflammation, triggered by the activation of the intraepithelial immune cells such as macrophages.