The invention concerns a composition made from at least one sulphated polysaccharide, in particular from an algae, and combined with at least one food ingredient. This composition can be used, in particular, in the field of food or in the treatment or prevention of an infection caused by microsporidia in humans or animals. It has useful properties as an antiparasitic agent in humans or animals； for the treatment or prevention of an infection caused by at least one microsporidia in humans or animals； in particular for the treatment or prevention of an infection caused in bees by the microsporidia Nosema, preferably Nosema ceranae or Nosema apis, or indeed for stimulating the immune defences of bees.
