The invention provides a yeast-derived material from yeasts of the genus Candida and/or the genus Kluyveromyces for the prevention or amelioration of plant-induced enteritis in fish. The yeast derived material is preferably intact or ruptured cells of and/or a cell fraction of the said yeasts. Also provided are fish feeds comprising said yeast-derived material for the prevention or amelioration of plant-induced enteritis in fish, as well as such feeds in combination with an enteritis-causing plant material, which may comprise a reduced fishmeal content and/or enhanced plant ingredient content relative to conventional fish feeds.
