Brief Bio: I am an Associate Professor at the Department of Fundamental Microbiology at the University of Lausanne, Switzerland. My major research interests lies in understanding the ecology and evolution of host-associated microbiomes and to unravel the molecular crosstalk between the microbiota and the host. Social bees are our favorite study system as their gut microbiota is evolutionarily conserved, functionally relevant, and experimentally tractable. This allows us to combine bioinformatics and genomics with experimental approaches to further our understanding of microbiota-host interactions.

Microbiome, honey bee host

The gut microbiota affects the social network of honey bees

The gut microbiota influences many aspects of animal physiology including neurodevelopment and behaviour. In vertebrate model organisms, gut symbionts have been shown to increase host responsiveness to social stimuli. However, it remains unclear whether these effects are widespread in the animal kingdom and how individual-level changes in social responsiveness affect the emergent properties of animal societies. The honey bee presents an attractive and relevant model to study such aspects of gut microbiota – host interactions due to the eusocial lifestyle and ecological importance of the host, and the experimental tractability of its gut symbionts.
Through a combination of gene expression analyses, cuticular hydrocarbon profiling, and automated behavioural tracking, we investigated the gut microbiota – brain axis in the honey bee. Our experimental design allowed us to control for the transition from nursing to foraging, which we found to play a major role in honey bee physiology and behavior even under laboratory conditions. We show that while the gut microbiota induces relatively small gene expression changes in the brain and no marked change in odorant profiles, it affects the colony social network structure by increasing the frequency and altering the patterning of pairwise social interactions. Our results suggest that the gut microbiota - brain axis regulates patterns of social interactions that are at the root of honey bee colony performance.