Lipid and n-3 PUFA effects on gut microbiome of Atlantic salmon

Over the years, researchers have adjusted dietary lipid:protein ratios and n-3 long-chain polyunsaturated fatty acids (LC-PUFA) to optimise feed resources and the growth performance of Atlantic salmon. However, knowledge of impacts from such dietary changes on the gut microbiome is lacking, especially under varying environmental conditions, e.g. reduced dissolved oxygen. For 116 days, post-smolt salmon (184 g) were fed diets with lipid:protein ratios considered high (460 : 230 g/kg) and low (180 : 570 g/kg). Additionally, each set of diets also varied in their level of n-3 LC-PUFA (7 or 14 g/kg) and salmon were reared under low and high levels of dissolved oxygen (6.7 or 8.0 mg/L). At day 0, 35 and 116, digesta in the distal intestine was collected and analysed for viable counts and 16S rRNA genes (V4 region) using Illumina Miseq.