The present study aimed to investigate the growth performance, whole body composition, and intestinal microbiome of selected and non-selected rainbow trout strains in response to a whole plant-based diet and genotype. For this purpose, a non-selected (ITA) and selected rainbow trout (USA) were fed with two different diets either a commercial fishmeal-based feed (C) or an all-plant protein feed (PP) including a high percentage of soy-based proteins. USA strain was developed using selective breeding based on growth performance when fed all-plant protein feeds by University of Idaho in collaboration with the United States Department of Agricultural – Agricultural Research Service (USDA-ARS).