Gut microbiome analyses of rainbow trout fed black soldier fly meal and its components of protein, oil and chitin

Research is lacking to understand if oil and chitin should be removed from black soldier flies (BSF; Hermetia illucens) meal and whether these components have beneficial effects on fish health. The aim of this study was to investigate the effects of feeding BSF meal and its components on plasma biochemistry, gut histology and gut microbiome of juvenile rainbow trout (Oncorhynchus mykiss; 29.63 g) in two consecutive 12-week feeding trials with fishmeal (non-stressed) and soybean-based diets (stressed). Fishmeal and fish oil were replaced with 5 and 10% full-fat BSF, 5 and 10% defatted BSF, 4% BSF oil and 1% BSF chitin.