Microbiome changes are associated with behavioral maturation in the honey bee, Apis mellifera

Gut microbiomes are increasingly recognized for the roles they play in mediating complex phenotypes of their hosts. In insects, gut microbes are known to play a role in health, immunity, and behavioral phenotypes. But, the specific functions that gut microbes perform in mediating behavioral phenotypes are not well studied. We are testing whether and how gut microbes influence behavioral phenotypes by identifying and studying the function of specific gut microbes in behavioral maturation and gut-brain communication in adult worker honey bees. We performed 16S rRNA sequencing coupled with quantitative real-time PCR analysis to identify specific changes in the gut microbiome that occur as honey bees transition from working in the hive performing brood care and other tasks to foraging outside. We found that overall gut microbial community structure consistently differed between nurse and forager bees across natural and experimental colonies. This change is due in part to changes in the abundance of three specific gut microbes: a decrease in Lactobacillus mellis and Lactobacillus melliventris and an increase in Bifidobacterium asteroides. Our ongoing work includes behavioral, genomic, metabolomic and gene editing studies to investigate the function of these specific microbes in behavioral maturation, and to identify specific ways that gut microbes communicate with the brain to influence host behavior.