Impacts of diet on hindgut microbiota and short-chain fatty acids in grass carp (Ctenopharyngodon idellus)

Diet is known to influence intestinal microbiota in fish, but the specifics of these impacts are still poorly understood. Different protein/fibre ratio diets may result in differing structures and activities of gut microbiota. We examined the hindgut microbiome of grass carp (Ctenopharyngodon idellus) fed three different diets: fish meal (FM, high protein - low fibre), Sudan grass (SG, high fibre - low protein) and compound feed (CF, intermediate). Microbial profiles of fish fed on FM were significantly different from profiles of fish fed CF and SG (F = 18.85, p CF>SG). Overall low SCFA levels indicate that hindgut fermentation probably provides a low proportion of energy requirements in grass carp