Probiotic Treatment with a Gut Symbiont Leads to Parasite Susceptibility in Honey Bees.

Gut symbionts are critical for host health and as such might be used as probiotics. In a recent study, Schwarz et al. showed that pretreatment of honey bees with a dominant gut bacterium causes dysbiosis and increases pathogen susceptibility, showing that probiotic applications for animal health can have unwanted effects.