Saccharomyces cerevisiae enhances immune resistance in paper wasps. Trained immunity in wasps

Although insects lack an acquired immune component, as occurs in vertebrates, thus relying only on an innate component of immune system, they have expanded it upon traits of plasticity and adaptation against pathogens in the form of immune priming. The recent discovery that wasps are an ecological niche of Saccharomyces cerevisiae, suggests that insects should have evolved a mechanism to tolerate and possibly benefit from the presence of this microorganism. We demonstrate that two yeast strains of Saccharomyces cerevisiae, previously shown to induce trained immunity in mammals, enhance resistance to bacterial infection in the paper wasp Polistes dominula, measured as bacterial clearance. Gut microbial community were studied with metataxonomy to evaluate changes caused by the experimental treatment.