A recent collaborative study by Canadian and Iranian researchers suggests that probiotic and prebiotic supplements may enhance honeybee survival under extreme temperature conditions. The findings, published in the open-access journal PLOS One, offer potential strategies to mitigate the significant bee colony losses that pose a risk to agriculture and ecosystems.

Honeybees play a critical role in agriculture, contributing an estimated $7 billion annually in harvest value across Canada. The country, ranked as the 12th-largest honey producer globally, generated 84,000 pounds of honey in 2025. However, honeybee colonies in Canada have suffered substantial winter losses, with nearly 40 percent of colonies lost during the 2024-25 season. Contributing factors to these declines include parasitic mites, starvation, and temperature extremes.

The research, involving academics from both Canada and Iran, targets temperature stress at opposite ends of the spectrum. While Canadian studies typically focus on cold-related colony mortality, Iranian researchers address the challenges bees face in high heat. Iran ranks as the world’s fifth-largest honey producer and similarly relies heavily on honeybees for pollination to support agricultural productivity.

Researchers tested the survival of bees exposed to temperatures of 4, 15, 35, and 40 degrees Celsius after consuming sugar water supplemented with varying concentrations of probiotics and prebiotics. Probiotics are live bacteria beneficial to gut health, and prebiotics are dietary fibers that promote the growth of these bacteria. Bees receiving the supplements demonstrated longer survival times compared to those without supplementation, with higher concentrations of the supplement mixture yielding better results.

The underlying mechanisms behind the enhanced survival remain unclear. The study hypothesizes that probiotics may help bees conserve energy by improving nutrient absorption and digestion, which in turn allows more energy to be directed toward temperature regulation. Probiotics may also bolster the immune system, helping bees withstand infection during stress induced by extreme temperature fluctuations.

Rassol Bahreini, a senior researcher at the University of Alberta and co-author of the study, noted that while winter mortality is a primary concern in Canada, increasing summer heat is becoming an emerging threat. "In Canada, we are focused on reducing winter mortality, but in Iran, the challenge is coping with heat stress," Bahreini explained.

Independent expert Leonard Foster, a honeybee researcher at the University of British Columbia not involved in the study, described the results as a promising contribution to the field. He emphasized the importance of exploring whether these supplements might provide resilience to other environmental stressors, such as drought or pesticide exposure, areas Bahreini’s team plans to investigate further.

While cooler temperatures can be mitigated through hive insulation and design, Foster highlighted that rising temperatures pose a more difficult challenge to manage. "Those we have a harder time controlling," he said, underscoring the urgency of developing solutions to protect bee populations amid changing climate conditions.