The effect of plant extracts on microbiota composition of healthy and Nosema-infected bees

The experiments aimed to investigate the effect of Scleranthus perennis and Hottonia palustris extracts on the bacterial microbiota composition of healthy and Nosema-infected honeybees (Apis mellifera). This allows us to verify the research hypothesis that the increased resistance to Nosema in bees supplemented with plant extracts is due to a change in the composition of their microbiota. The bee microbiota composition was analyzed using 16S rRNA gene metabarcoding. There were six experimental groups: insects supplemented with H. palustris extract; group 2, insects supplemented with S. perennis extract; and group 3 (control), unsupplemented insects, both healthy and infected. Using preparations based on plant extracts containing bioactive metabolites as dietary supplements may provide a natural tool for protecting honey bees against pathogens. Such supplementation likely positively impacts bee health by modulating the composition of the gut microbiome. Therefore, further research is required to understand the functions of the microorganisms inhabiting the bee gut. This offers hope for the development of new and effective preparations to combat pathogens that attack the bee gut, such as Nosema spp.