Honey bee (Apis mellifera) gut microbiota promotes host endogenous detoxification capability via regulation of P450 gene expression in the digestive tract

There is growing number of studies demonstrating a close relationship between insect gut microbiota and insecticide resistance. However, the contribution of the honey bee gut microbiota to host detoxification ability has yet to be investigated. In order to address this question, we compared the expression of cytochrome P450s (P450s) genes between gut microbiota deficient (GD) workers and conventional gut community (CV) workers and compared the mortality rates and the pesticide residue levels of GD and CV workers treated with thiacloprid or tau‐fluvalinate. Our results showed that gut microbiota promotes the expression of P450 enzymes in the midgut, and the mortality rate and pesticide residue levels of GD workers are significantly higher than those of CV workers. Further comparisons between tetracycline‐treated workers and untreated workers demonstrated that antibiotic‐induced gut dysbiosis leads to attenuated expression of P450s in the midgut. The co‐treatment of antibiotics and pesticides leads to reduced survival rate and a significantly higher amount of pesticide residues in honey bees. Taken together, our results demonstrated that honey bee gut symbiont could contribute to bee health through the modification of the host xenobiotics detoxification pathways and revealed a potential negative impact of antibiotics to honey bee detoxification ability and health.