Balanced replacement of fish meal with Hermetia illucens meal allows efficient hepatic nutrient metabolism and increases fillet lipid quality in gilthead sea bream (Sparus aurata)

In the present study, gilthead sea bream (Sparus aurata) was reared using sustainable feeds containing insect meal
from Hermetia illucens larvae. Proteomics and proton nuclear magnetic resonance-based metabolomics analysis
were used to assess the metabolic impact of the tested feeds in sea bream liver, whereas the composition of
muscle fillets was characterized by means of metabolomics and gas chromatography of fatty acid methyl esters.
Including 10% of insect meal while correspondingly reducing fish meal did not substantially alter the metabolism
of dietary nutrients, leading to small but significant effects solely on lauric acid content of sea bream fillets.
Furthermore, a few alterations in some markers of immune response, such as leukocyte elastase inhibitor-like,
granzyme B (G, H)-like, and two associated ortholog groups, serpin B and chymase, were found. In the fish
group fed with insect meal, liver morphology analysis showed no structural damage or inflammation and a lower
amount of hepatic lipid deposition and accumulation.