A bee collects nectar and pollen from a sunflower in Remseck, in the German region of Baden-Württemberg.Bernd Weißbrod/The Associated Press
Probiotic and prebiotic supplements may improve the survival rate of honeybees in extreme temperatures, according to a new study co-authored by Canadian and Iranian researchers.
Beekeeping, from honey production to pollination services, brings an estimated $7-billion in harvest value across Canada, according to Agriculture and Agri-Food Canada. In 2025, the hard-working insects produced 84,000 pounds of honey, making Canada the twelfth-largest producer of honey worldwide.
Every winter, honeybee colonies experience significant losses, with 39.3 per cent of bee colonies lost in 2024-25. A parasitic mite, starvation and extreme temperatures were the main causes of this loss.
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However, giving honeybees probiotic and prebiotic supplements could help reduce those losses, and help keep bees alive through fluctuating temperature conditions, according to a study published Wednesday in the peer-reviewed, open-access journal PLOS One.
Probiotics are live bacteria beneficial to gut health, while prebiotics are fibre compounds that bacteria can digest but animals cannot.
The research was conducted by academics in Canada and Iran. Both countries face extreme heat-related issues with their bees, but on opposite ends of the thermometer.
Honeybees fly in and out of a bee hive at a Simon Fraser University experimental apiary in Surrey, B.C., in 2022.DARRYL DYCK/The Canadian Press
“In Canada, we are focused on research to reduce winter mortality for beekeepers. In Iran, where the climate is hot, the challenge is the opposite,” said Rassol Bahreini, a senior researcher at the University of Alberta and one of the authors of the study.
Iran is the fifth-largest producer of honey worldwide, after China, India and Turkey, according to 2024 data from the Food and Agriculture Organization of the United Nations. Similar to Canada, Iran depends on the contributions of pollinators, including honeybees, for its agricultural production.
Dr. Bahreini said most bee research in North America and Europe typically focuses on winter losses rather than high temperatures, which can also have detrimental effects on bee colony survival. As the summer season gets progressively warmer in Canada, the stress that bees face from hot conditions becomes a greater concern.
An optimal temperature for bees is around 35 degrees Celsius. They can be in danger once temperatures drop to around 4 C or exceed 40 C.
The findings showed that bees exposed to temperatures of 4, 15, 35 and 40 C after consuming sugar water supplemented with prebiotics and probiotics survived for longer than their non-supplemented counterparts, and a higher concentration of the supplement mix led to a higher survival rate.
It’s not known exactly how supplementing the bacteria in a bee’s gut appears to improve its survival. However, the study said probiotics are generally considered to improve the bee’s ability to conserve energy, allowing it to focus its efforts on regulating temperature.
The probiotic and prebiotic supplements may be able to help the bees conserve energy by assisting with the absorption of nutrients and digestion of their food, according to the study. Probiotics can also improve the immune response of bees, protecting them from infections during periods of stress induced by extreme weather.
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In a forthcoming paper, Dr. Bahreini expects to examine whether probiotic and prebiotic supplements improve bee survival against pesticides.
Leonard Foster, a honeybee researcher at the University of British Columbia who was not involved in the study, also said he’s curious if the effects of the supplements could be generalized for other stressors, such as drought tolerance.
He said the results of this study are significant to honeybee research.
“It starts to look at how we can change how we’re managing bees in order to maybe mitigate some of the impacts of heat stress,” Dr. Foster said.
While both extreme heat and cold are worrying for bee survival, cooler temperatures can be physically mitigated by insulating beehives and reducing drafts, Dr. Foster said.
“The direction that is more worrisome for most people right now is the higher temperatures,” he said. “Those we have a harder time controlling.”