The genetic diversity of honeybee colonies predicts the gut bacterial diversity of individual colony members

O_LIThe gut microbiota of social bees is relatively simple and dominated by a core set of taxa that have been reported consistently in individual workers from around the world. Yet, variation remains, and this has been shown to affect host health. C_LIO_LIWe characterised the individual- and regional-scale variation in the honeybee (Apis mellifera) gut microbiota in the North West of England, and asked whether the microbiota was influenced by host genotype or landscape composition. C_LIO_LIWe collected multiple honeybees from 64 colonies, and sequenced the V4 region of the 16S rRNA gene to characterise the mid- and hindgut bacterial communities. We characterised the genotype of each individual honeybee, and also the land cover surrounding each colony. C_LIO_LIThe literature-defined core taxa consistently dominated across the region, despite the varied environments. However, there was variation in the relative abundance of core taxa, and colony membership explained a large proportion of this variation. Individuals from more genetically diverse colonies had more diverse microbiotas, but individual genetic diversity did not influence gut microbial diversity. There was a trend for colonies in more similar landscapes to have more similar microbiota, whilst bees from more urban landscapes had a slightly less diverse microbiota than those from less urban landscapes. C_LIO_LIOur study provides, to our knowledge, the first demonstration for any species that the gut bacterial communities of individuals can be influenced by the genotypes of other conspecifics in the population. This is particularly important for social organisms, such as honeybees, as colony rather than individual genetic diversity appears to drive gut microbial diversity, a factor related to colony health. C_LI