Most flowers are occupied by diverse communities of microbes, which can alter floral attractiveness to key pollinators and floral fitness by interacting with floral traits. Different species of flower often acquire unique communities of microbes. Consequently, pollinators are frequently forced to choose between two flowers with distinct floral microbiomes while foraging. However, it is currently unknown whether pollinators have an inherent preference for flowers containing one floral microbiome over another, and whether microbial preference is modified by variation in floral traits. We investigated this knowledge gap using distinct bacteria and yeasts cultured from a nickel-hyperaccumulating plant (Streptanthus polygaloides) and its non-accumulating relative (S. tortuosus). Specifically, we hypothesized that 1) bumblebee foraging preference (initial, overall and over time) depends on the interaction of microbiome origin (hyperaccumulator vs non-accumulator isolated) and nectar metal content, and 2) that bumblebees exhibit the greatest floral fidelity (successive visits to the same kind of flower) when flowers vary in both microbiome composition and nectar metal concentration. To test these hypotheses, we observed foraging patterns of lab-reared eastern bumblebees on arrays of artificial flowers containing nectar treatments of nickel/no-nickel, hyperaccumulator microbes/non-accumulator microbes or a cross of metal-by-microbe treatments. Microbial community treatments were synthetic and assembled from the most abundant bacterial and fungal taxa found on wild hyperaccumulator and non-accumulator flowers. Bumblebees initially had a preference against nectar containing nickel and non-accumulator microbes. Across all visits in the trial, bumblebees expressed no variation in preference among nectar treatments and preference did not shift over the course of each trial. Bees also did not exhibit variation in constancy when presented with different kinds of treatments. Together our results suggest that variation in floral microbiome composition does not drive strong foraging patterns in bumblebees. More broadly our suggest that the simple presence or absence of microbes living in a flower may be a stronger component of pollinator foraging patterns than variation among existing microbiomes.