MODULATION OF EUROPEAN SEA BASS (Dicentrarchus labrax) GUT MICROBIOTA BY DIETARY INSECT MEAL

The aquaculture industry is one of the fastest growing industries of its sector, mostly due to the incremental demand of fish production. However, this generates resource management issues mainly in the use of fish meal (FM), which becomes both ecologically and economically unsustainable. To respond to this issue, novel dietary ingredients are being studied to formulate aquafeeds with suitable dietary profiles for each species. With a high protein and lipid contents, a balanced amino acid profile and a recent authorization for the incorporation in aquafeeds in the European Union, insect meal (IM) positions itself as a strong candidate for FM substitution. Introduction of novel ingredients, however, can impact over the fish immune status and/or growth performance. One of the known effects of introducing novel dietary ingredients is the potential to generate gut microbial communities shifts which are recognized to impact on fish growth, metabolism, and immune status (Ringø et al. 2015; Ringø et al. 2018; Serra et al. 2021). In fact, prebiotic effects have been attributed to IM, with these being commonly associated with the increase of dietary chitin, a structural polysaccharide present in the insects exoskeleton (Perry et al. 2020) However, information about the potential gut microbiota shifts occurring as a consequence of dietary IM inclusion are scarce (Perry et al. 2020). Thus, this study aims to assess the effect of three different IM, namely, Hermetia illucens larvae meal (HM), Tenebrio molitor larvae meal (TM), and H. illucens exuviae meal (HEM) on European seabass gut microbiota modulation