A propolis-rich hive environment affects redox gene expression and gut microbiota at the individual and social level in honey bees

Authors: Anderson, Kirk; Copeland, Duan; Mott, Brendon; KORTENKAMP, OLIVER - University Of Arizona; Erickson, Robert; ALLEN, NATHAN - University Of Arizona; MAES, PATRICK - University Of Arizona; CHAO, NAOMI - University Of Arizona; DALENBERG, HOLLIE - University Of Minnesota; SPIVAK, MARLA - University Of Minnesota

Submitted to: FEMS Microbes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/2026
Publication Date: 4/16/2026
Citation: Anderson, K.E., Copeland, D.C., Mott, B.M., Kortenkamp, O.L., Erickson, R.J., Allen, N.O., Maes, P., Chao, N., Dalenberg, H., Spivak, M. 2026. A propolis-rich hive environment affects redox gene expression and gut microbiota at the individual and social level in honey bees. FEMS Microbes. 7:2026 xtag019. https://doi.org/10.1093/femsmc/xtag019.
DOI: https://doi.org/10.1093/femsmc/xtag019

Interpretive Summary: The Problem: Honey bees face numerous health challenges including nutrient poor forage, agricultural chemicals, multiple pathogens and parasites that contribute to unpredictable colony loss—an average of 60% annually for commercial beekeepers in each of the last two years. Maintaining colony health in the face of multiple stressors requires constant attention and financial resources from the beekeeper. The Accomplishment: Here we demonstrate a simple colony-level strategy to promote good health: roughing up the smooth wooden interior of the hive box. This action prompts the colony to collect tree resin and produce propolis to fill the irregularities, a process that spreads propolis, a complex substance with antioxidant, antimicrobial and antiviral activity throughout the social colony environment. Using full-sized colonies, we prompted workers to collect tree resin creating a naturally propolis-rich colony/hive environment. In propolis-rich colonies, we found significantly larger populations of core (beneficial) bacteria in the worker gut, improved host immunity and host response to oxidative stress compared to propolis-poor colonies. Our study suggests that propolis supplementation has a net positive effect on host-microbial health at both individual and social levels. The Contribution: Encouraging the collection of resin and production of propolis via a simple hive alteration contributes to healthy gene expression and microbiota in honey bees. With minimal effort, beekeepers can introduce a rough textured hive interior, stimulating the collection of resin. This simple action not only fosters microbial, immune and redox health through the upregulation of internal and socially secreted enzymes, but may also aid in the detoxification of biocides prevalent throughout the pollination environment.

Technical Abstract: The microbiome of the honey bee is associated with immunity, oxidative state, and disease susceptibility. Here we investigated the effects of increased colony-level propolis exposure on gut microbiota and host worker immune and redox gene expression. Sampling pre-marked adult worker bees at 9-days post emergence revealed significantly larger populations of core microbiota in worker guts from propolis-rich colonies, but little change in taxonomic composition or relative structure. We found an overall trend towards decreased expression of immune genes in propolis-rich colonies. The expressions of both pro-phenol oxidase and catalase were significantly reduced in the worker fat body suggesting that propolis-rich colonies better support host redox balance in individual workers. Increased propolis levels resulted in greater expression of superoxide dismutase from the worker fat body and social head glands, consistent with tissue-specific expression considered beneficial in model organisms and humans. Our results suggest that propolis-rich conditions and social head gland secretions contribute to total redox activity throughout the niche space of social immunity. Moreover, our results are consistent with a companion paper that sampled the same colonies and age cohorts, reporting drastic increases in beneficial native bacteria and reduced pathogen prevalence on the mouthparts, a primary marker of social immunity.