Impact of sugar syrup and pollen diet on the bacterial diversity in the gut of indoor-reared bumblebees (Bombus terrestris)

Abstract

In this project, we showed the influence of diet on the microbial composition in the gut of indoor-reared bumblebees (Bombus terrestris), using Illumina MiSeq 16S ribosomal RNA (rRNA) sequencing. Three sugar syrups and sterilized pollen from three suppliers were tested. Different effects were observed depending on the developmental stage of the gut microbiota at the start of the dietary treatment. Fructose-rich sugar syrup prevented the colonization of Bifidobacteriaceae in the microbiota of newly emerged bumblebees. This effect was correlated with a lower bacterial community richness and diversity. The pollen diet with the best parameters, regarding the protein content and bumblebee offspring, showed the lowest bacterial richness and diversity. The interaction between diet and the microbiota of bumblebees provides new insights for bumblebee breeders. Diet could be used to modulate the bacterial composition in the gut to improve the health of mass-produced bumblebees used for biological pollination.