Honey bees rely on more than just pollen and nectar to stay healthy. Inside their digestive system lives a complex community of microbes that play a vital role in their survival. This blog explores the honey bee gut microbiome, how it changes with the seasons and why nutrition and microbial balance are essential for colony health.

Bee Healthy: Inside the Gut!

The gut microbiome includes all the organisms that live in the digestive tract. Examples of these organisms include bacteria and fungi. Bacteria that live in the honey bee gut microbiome can be core bacteria, which form a consistent community of cells, or non-core bacteria like Bartonella, Commensalibacter and Frischella ¹. Common fungi in adult Honey bees are Ascomycota, Basidiomycota, Glomeromycota, Zygomycota, and the fungus Saccharomyces, which is common in young bees ¹.  The microbiome aids in the digestion of food and absorption of nutrients, helping bees get the most out of their diet. Proper nutrients support a strong immune system, which protects against harmful pathogens. Beyond digestion, the microbiome also influences other important systems in the bee’s body, including endocrine signaling, olfactory processing and memory pathways ¹. Disturbances to the gut microbiome, caused by stress or poor nutrition, can interfere with bee development and influence gene expression related to their immunity, metabolism, and behaviour¹.

Inside the bee’s gut, there are five core beneficial bacteria. These belong to the genera Bifidobacterium, Bombilactobacillus, Gilliamella, Lactobacillus, and Snodgrassella, and are present in healthy honey bees¹. These bacteria are passed between the bees through social contact and help maintain gut stability. To support these microbes, bees rely on a diet rich in macronutrients and micronutrients. Macronutrients like pollen and nectar are needed in large amounts. Pollen provides honey bees with proteins, lipids, vitamins, and essential sterols, while nectar is their main source of carbohydrates ².  Micronutrients, though required in trace amounts, are equally vital. These include vitamins, minerals, phytochemicals and phytosterols, all of which support bee health ³.

Figure 1: Honey bee eating honey  (ATTTA ©, 2018)

Nutritional supplements also play an important role in helping bees rebuild their gut microbiome and immune system, especially in early spring when natural forage is limited. There are many types of supplements available, including pollen patties for protein and lipid support, probiotics that introduce beneficial bacteria, and prebiotics that help existing gut microorganisms survive. When used appropriately, these supplements could support immune function and reduce pathogen loads. However, they should be given to boost the digestive system of bees and not be used as a replacement for natural forage. Some research is required to fully understand the benefits of nutritional supplements to overall bee health.

The structure of the bee’s digestive system also influences where microbes live. The crop temporarily stores nectar inside the bee ⁴. The midgut is where enzymes are secreted to aid digestion and nutrient absorption ⁴. The crop and midgut do not have stable bacteria because they are exposed to external microbes that enter the digestive tract ⁵. The hindgut, which includes the ileum and rectum, is where most of the core beneficial bacteria reside. It provides a more stable environment for the helpful microbes ⁵. This is also where water and mineral reabsorption occur, and processing of metabolic waste ⁴. Honey bees also have Malpighian tubules, which act like kidneys, excreting waste products into the hindgut to be removed from the body ⁴. 

Figure 2: Digestive Anatomy of a Honey bee (ATTTA ©, 2025)

Honey bee gut microbiome does not just vary between individual bees but also changes with the seasons. While the total number of bacteria in the gut remains relatively stable year-round, the diversity and composition of those bacteria shift depending on the environmental conditions ⁶.  In spring, microbial diversity is highest, likely from the new foraging activity and exposure to a wide range of pollen and nectar sources ⁶. In summer and winter, diversity tends to decrease, with Gilliamella and Snodgrassella becoming the dominant bacteria ⁶. These seasonal shifts are influenced by temperature, precipitation and forage availability, all shape the microbial community in the bees’ gut. A diverse and balanced microbiome in spring helps bees recover from the winter stress and prepare for the active seasons ahead.
 
Maintaining a healthy gut microbiome is essential for honey bee health, especially in spring, when colonies are rebuilding after winter. Understanding what goes on inside the bees’ gut and ensuring they receive proper nutrients and microbial support can help beekeepers promote stronger colonies.

Written by Kaitlyn Newton, ATTTA Seasonal Apiculturist 

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email attta@perennia.ca

References:

1.    Motta, E.V. and Moran, N.A., 2024. The honeybee microbiota and its impact on health and disease. Nature Reviews Microbiology, 22(3), pp.122-137.

2.    Khan, K.A., Ghramh, H.A., Ahmad, Z., El-Niweiri, M.A. and Mohammed, M.E.A., 2021. Honey bee (Apis mellifera) preference towards micronutrients and their impact on bee colonies. Saudi Journal of Biological Sciences, 28(6), pp.3362-3366

3.    Tsuruda, J.M., Chakrabarti, P. and Sagili, R.R., 2021. Honey bee nutrition. Veterinary Clinics of North America: Food Animal Practice, 37(3), pp.505-519

4.    De Paula, J.C., Doello, K., Mesas, C., Kapravelou, G., Cornet-Gómez, A., Orantes, F.J., Martínez, R., Linares, F., Prados, J.C., Porres, J.M. and Osuna, A., 2022. Exploring honeybee abdominal anatomy through micro-CT and novel multi-staining approaches. Insects, 13(6), p.556.

5.    Romero, S., Nastasa, A., Chapman, A., Kwong, W.K. and Foster, L.J., 2019. The honey bee gut microbiota: strategies for study and characterization. Insect molecular biology, 28(4), pp.455-472.

6.   Castelli, L., Branchiccela, B., Romero, H., Zunino, P. and Antúnez, K., 2022. Seasonal dynamics of the honey bee gut microbiota in colonies under subtropical climate: Seasonal dynamics of honey bee gut microbiota. Microbial ecology, 83(2), pp.492-500.

Whether you are a seasoned beekeeper with years of experience, or just starting out on your apiary journey, it is always important to revisit the basics. By refreshing your memory, or reinforcing seemingly straightforward topics, diving back into fundamentals can greatly enhance your understanding of beekeeping. In honey bee hives there are numerous cells that are built from wax by the bees. These cells serve various functions, including storing food and taking care of brood.  This week we will explore some facts about honey comb cells.

What the Cell?

Honey bees construct hexagonal cells which make up the comb found on frames in the hive. Worker cells, which contain developing female or worker bees, can have an approximate size of 5.20-5.40 mm, and drone cell, where male bees develop,  sizes can range from 6.20-6.40 mm⁶. The cell are constructed using beeswax that the bees produce from a secretory gland in their abdomen¹. These cells are used for different purposes. Nurturing brood and storing food are both functions of the different cells.  By understanding what the different types of cells should look like, beekeepers can help to keep the hive well balanced and healthy. By recognizing these different cell types, beekeepers can also understand hive changes such as when a colony is going to swarm. 

Queen, eggs, drone, capped brood, honey, pollen (©ATTTA 2022)

Nectar, which is an aqueous solution of sugars, amino acids and minerals, is gathered from flowers by honeybees to bring back to the hive using their honey stomach². Once the forager bee gets back to the hive, it passes on the nectar to a receiver bee, and sucrase gets added to the nectar before being placed in the cell².  Sucrase is an enzyme that breaks down sucrose into simpler sugar molecules². It is the job of the receiver bee to break down sucrose, but both forager and receiver bees have the enzyme sucrase⁷.  The water must be evaporated from the nectar to increase sugar concentration and form honey. Nectar starts at a water content as high as 80% and the bees reduce it to approximately 17-20%². By evaporating most of the water, it also helps to store the honey long term, because fermenting organisms cannot live there². Bees actively evaporate nectar by regurgitation and re-ingesting droplets, and passive evaporation is also done by bees using a fanning behavior³ . Once the moisture content is low, and the honey is ripe, it will be capped off with a thin layer of wax so it can be stored indefinitely⁴ . Honey is hygroscopic, so if the bees cap it the moisture from the environment should not re-enter the cell, which prevents fermentation⁸. The honey is then used for food when bees cannot forage for nectar.

Cells with capped and uncapped honey (©ATTTA 2024)

Pollen is attracted to the bees and is transferred from the anthers of flowers². Pollen is an important source of nutrients for bees because it contains a proteins, lipids, vitamins, and minerals⁵. Bees collect pollen using a small amount of nectar to make the pollen stick and give it beneficial bacteria, then they put it into pollen baskets on their back legs, known as corbiculae². When back from foraging the honeybees back push the pollen pellets off their legs into an empty cell, or one half filled with pollen. Housekeeping bees then pack the pollen and add nectar from their honey sac to start a fermentation process². The microflora of pollen contains bacteria, yeasts and molds which all play a role in fermentation⁹. But primarily the process is driven by the lactic acid bacteria, which produces lactic acid playing a crucial role in preserving the bee bread¹⁰. This is how beebread is formed, and bees sometimes cap the cells with honey to preserve it since it does not last as long as honey does².

In a well-organized hive bees exhibit remarkable precision in arranging their food and offspring.  The outer frames mostly contain food stores. Within a single frame, bees construct an arching figure where honey is stored in the upper cells, followed by a layer of pollen beneath, and finally, the lower cells are designed for brood. Typically, the brood is concentrated in the center of the hive in an area called the brood nest. This interesting aspect of bee behavior will be explored further in an upcoming blog post.

Written by Kaitlyn Newton, ATTTA Seasonal Apiculturist

References:

1. Xu, R., Ma, B., Yang, Y., Dong, X., Li, J., Xu, X. and Fang, Y., 2024. Proteome-metabolome profiling of wax gland complex reveals functional changes in honeybee (Apis mellifera L.). iScience.

2. Sammataro, D. and Avitabile, A., 2021. The beekeeper’s handbook fifth addition. Cornell University Press.
3. Nicolson, S.W., Human, H. and Pirk, C.W., 2022. Honey bees save energy in honey processing by dehydrating nectar before returning to the nest. Scientific Reports, 12(1), p.16224.
4. Fernandes, K.E., Frost, E.A., Remnant, E.J., Schell, K.R., Cokcetin, N.N. and Carter, D.A., 2022. The role of honey in the ecology of the hive: Nutrition, detoxification, longevity, and protection against hive pathogens. Frontiers in Nutrition, 9, p.954170.
5.  Huang, Z., 2010. Honey bee nutrition. American Bee Journal, 150(8), pp.773-776.
6.  Zhang, L., Shao, L., Raza, M.F., Han, R. and Li, W., 2024. The Effect of Comb Cell Size on the Development of Apis mellifera Drones. Life, 14(2), p.222.
7.  Zhu, Y.C., Caren, J., Reddy, G.V., Li, W. and Yao, J., 2020. Effect of age on insecticide susceptibility and enzymatic activities of three detoxification enzymes and one invertase in honey bee workers (Apis mellifera). Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, 238, p.108844
8. Kubásek, J., Svobodová, K., Půta, F. and Krejčí, A.B., 2022. Honeybees control the gas permeability of brood and honey cappings. iScience, 25(11), p.105445.
9.  Miłek, M., Mołoń, M., Kula-Maximenko, M., Sidor, E., Zaguła, G. and Dżugan, M., 2023. Chemical Composition and Bioactivity of Laboratory-Fermented Bee Pollen in Comparison with Natural Bee Bread. Biomolecules, 13(7), p.1025
10.  Kieliszek, M., Piwowarek, K., Kot, A.M., Błażejak, S., Chlebowska-Śmigiel, A. and Wolska, I., 2018. Pollen and bee bread as new health-oriented products: A review. Trends in Food Science & Technology, 71, pp.170-180.

                                                    

                                                 Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca

In last week’s blog, we discussed the foraging behavior of honey bees while placed on almond orchards for pollination in Australia. In Atlantic Canada, honey bees are most heavily employed for the pollination of wild blueberries. Read on for insight into the foraging behavior of worker bees during this important period of the beekeeping season.

Honey Bee Nutrition in Wild Blueberry Fields

Providing wild blueberry pollination services is a major activity for many Atlantic Canadian beekeepers. Wild blueberries typically bloom in late May and early June, shortly after local forage sources have begun to proliferate. There are concerns that when bees are moved to blueberry fields, stress causes colonies to become weakened and susceptible to disease such as European foulbrood. In 2019, ATTTA did a study in Colchester county, Nova Scotia to explore this concern and improve our understanding of forage availability to honey bees (Olmstead et al. 2019).

Wild blueberry field in bloom. (ATTTA©2021)

ATTTA’s study explored nutritive health of pollinating honey bees by supplementally feeding and tracking hives during and after wild blueberry pollination. Seam counts and brood assessments revealed the colonies to be in good health. Colony growth and rate of EFB infection were not significantly different between hives fed pollen supplement and hives which were not. All colonies were at or above the Nova Scotia pollination standard for the duration of the trial and there were minimal instances of EFB.  In addition, pollen traps were mounted onto a sample of hives. After 24 hours, the collected pollen reflected a range of forage availability. 

The first published study to assess honey bee forage on wild blueberry fields in the Maritimes revealed that honey bees collected a very marginal amount of wild blueberry pollen during pollination (Colwell et al. 2017). This is distinct from honey bee pollination on almond orchards, where almond pollen is collected abundantly (Bezerra da Silva Santos et al. 2022). When honey bees are foraging on wild blueberry fields, they are nectar foraging (Javorek et al. 2002). They are moving from flower to flower, incidentally moving pollen in the process, but with the purpose of collecting nectar. Nectar is a valuable energy source for honey bees, while pollen provides protein and other nutrients that are important to honey bee health and brood rearing (Di Pasquale et al. 2013). When foraging wild blueberry fields, honey bees must rely on pollen from other resources.

ATTTA continued to sample pollen collections from honey bees during wild blueberry pollination in 2021 and 2022 to add to the breadth of knowledge that beekeepers and blueberry producers have about typical forage availability during this time. Stay tuned as we disseminate the results of these collections in upcoming meetings and publications. 

References

Bezerra da Silva Santos, Karen Cristine, Elizabeth Frost, Ulrika Samnegård, Manu E. Saunders, and Romina Rader. 2022. “Pollen Collection by Honey Bee Hives in Almond Orchards Indicate Diverse Diets.” Basic and Applied Ecology 64 (November): 68–78. https://doi.org/10.1016/j.baae.2022.07.006.
Colwell, Megan J., Geoffrey R. Williams, Rodger C. Evans, and Dave Shutler. 2017. “Honey Bee‐collected Pollen in Agro‐ecosystems Reveals Diet Diversity, Diet Quality, and Pesticide Exposure.” Ecology and Evolution 7 (18): 7243–53. https://doi.org/10.1002/ece3.3178.
Di Pasquale, Garance, Marion Salignon, Yves Le Conte, Luc P. Belzunces, Axel Decourtye, André Kretzschmar, Séverine Suchail, Jean-Luc Brunet, and Cédric Alaux. 2013. “Influence of Pollen Nutrition on Honey Bee Health: Do Pollen Quality and Diversity Matter?” Edited by Jochen Zeil. PLoS ONE 8 (8): e72016. https://doi.org/10.1371/journal.pone.0072016.
Javorek, S. K., K. E. Mackenzie, and S. P. Vander Kloet. 2002. “Comparative Pollination Effectiveness Among Bees (Hymenoptera: Apoidea) on Lowbush Blueberry (Ericaceae: <I>Vaccinium Angustifolium</I>).” Annals of the Entomological Society of America 95 (3): 345–51. https://doi.org/10.1603/0013-8746(2002)095[0345:CPEABH]2.0.CO;2.
Olmstead, Sawyer, Robyn McCallum, and Jillian Shaw. 2019. “Evaluating the Effect of Feeding Pollen Substitute to Honey Bee Colonies Destined for Wild Blueberry Pollinaiton in Cochester County, Nova Scotia.” Perennia.

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca

Honey bees are often used as either primary or supplemental pollinators in commercial agriculture. They are transported to flowering crop fields during the bloom period and subsequently returned to their home apiaries after providing pollination services. Honey bee nutrition depends on the colony’s surrounding floral sources, as this is where foragers can obtain pollen and nectar. Researchers in Australia have recently published a report which improves our knowledge of honey bee foraging behavior during crop pollination, read on to learn more about their encouraging findings. 

Honey Bee Nutrition in Commercial Pollination

In 2017, two Australian almond orchards were used as study sites to investigate the identity, quantity, and timing of pollen collection by honey bees used for pollination services (Bezerra da Silva Santos et al. 2022). In these orchards, beehives were distributed at several different locations within the fields. One orchard was stocked at 0.04 hives per hectare, holding 96 hives in 2,375 hectares, and the other was stocked at 0.06 hives per hectare, with 71 hives in a 1,200-hectare plot. Almond blossoms in this region are typically present in late August and early September for about two to four weeks. The colony placement preceded bloom by 7 days, and they then remained for 21 additional days of the full bloom period.  Pollen traps were placed on 80 colonies between the two fields and contents of trays were collected every 48 hours of the open bloom period. 

Foraging honey bees with yellow pollen packed in their corbiculae (ATTTA©2022).

This study demonstrated that honey bees collected an array of pollen varieties while placed on almond orchards. Seventy-nine percent of hives contained pollen from both non-almond and almond flowers.  This indicates that foragers were not limited to almond blossoms for nutrition. Almond pollen was most heavily collected at the beginning of the flowering period, with about 70% of all almond pollen collection being within the first three sampling days. This was the time at which there was the greatest number of open almond flowers. The researchers also found that the location within the orchards had no impact on the plant species of pollen collected. 

The results of this study are encouraging for beekeepers engaged in commercial pollination. It adds to the limited amount of research on honey bee nutrition during pollination. Wild blueberry pollination falls at a critical time for beekeepers in Atlantic Canada, as it is the beginning of our beekeeping season. There is nationwide concern among beekeepers regarding the health of their colonies during blueberry pollination, particularly related to nutritional stress (McAfee 2018). While wild blueberry pollination has important distinctions from almond pollination, the results of this study add to our general understanding of how honey bees forage on large, monoculture fields. This paper reflects that foragers are able to reach a variety of floral sources even in a vast orchard of almond blossoms. This is optimistic for beekeepers, as floral variety supports healthy honey bee nutrition (Donkersley et al. 2017).

In next week’s blog, we will discuss honey bee foraging as it relates more closely to wild blueberries and honey bee pollination in Atlantic Canada.   

References

Bezerra da Silva Santos, Karen Cristine, Elizabeth Frost, Ulrika Samnegård, Manu E. Saunders, and Romina Rader. 2022. “Pollen Collection by Honey Bee Hives in Almond Orchards Indicate Diverse Diets.” Basic and Applied Ecology 64 (November): 68–78. https://doi.org/10.1016/j.baae.2022.07.006.

Donkersley, Philip, Glenn Rhodes, Roger W. Pickup, Kevin C. Jones, Eileen F. Power, Geraldine A. Wright, and Kenneth Wilson. 2017. “Nutritional Composition of Honey Bee Food Stores Vary with Floral Composition.” Oecologia 185 (4): 749–61. https://doi.org/10.1007/s00442-017-3968-3.

McAfee, Ali. 2018. “The Blueberries and the Bees.” Bee Scene, 2018.

 Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca

Pollen: The Protein Source of Bees

Natural foods and health products has gained significant interest, especially over the past decade, as the link between good nutrition and good health has also gained interest in research studies. These studies help to provide a better understanding of the potential health benefits and applications of natural products, including various hive products. So far, in our ‘Hive Products for Human Health’ mini-series, we have discussed some health-related beneficial bioactivities and applications of honey, propolis, and beeswax. This week we are moving on to pollen; keep reading to learn about potential human health benefits of the protein source of bees: pollen.

What’s the Buzz with ATTTA Podcast Episode 10 is now available! Keep reading for a sneak peek of what this episode’s discussions are all about. 

We’ve began creating weekly “ATTTA Buzz” posts to share ATTTA news, announcements, and timely reminders intended for beekeepers in Atlantic Canada, but available to all others that are interested! We will be sharing these posts from our Twitter account (@beeatlantic) and through social media pages of some beekeepers’ associations and other beekeeping groups in our maritime region. Keep an eye out for the weekly ATTTA Buzz to stay up to date with what we’ve up to, we are glad to have you following along!

Pollen: The Protein Source of Bees

Pollen is collected by foraging worker bees and brought back to the hive to be made into bee bread used to feed larvae to provide essential proteins required for successful worker and drone brood production. A developing queen does not receive pollen in her diet. The pollen that is found stored within the hive is compositionally unique from its original form when it was produced by the flower from which it was collected. When bees collect pollen from a flower, they incorporate small amounts of nectar and a saliva-like substance that contains enzymes. This makes the pollen sticky enough to be packed neatly into a secure pellet in the worker bee’s ‘pollen basket’, located on her hindlegs. The composition of pollen itself is unique depending on the floral source, geographic location, and other environmental conditions; similar to honey and beeswax, as discussed earlier in this mini-series. Since foraging worker bees also add nectar and enzyme-containing saliva to the pollen to ready it for transport, compositional variation from these additions are also incorporated into the pollen. This is important to consider when discussing the composition and potential beneficial uses and therapeutic applications of honey bee collected pollen and pollen products (i.e., bee bread).

Antimicrobial and antioxidant activities of natural and fermented bee pollen *

Bee pollen is sold as a hive product for human health and nutrition in various forms including natural pollen pellets, capsules, powder, and also bee bread pellets and other forms of pollen that has undergone fermentation processes. Even if the same pollen source was used in a particular set of products, that include both pollen pellets and bee bread, the digestibility and bioactivities of the natural pollen and the fermented pollen tend to vary. Even between fermented pasteurized pollen and fermented natural pollen, the bioactivities of the product can vary. This study aimed to evaluate the bioactivities of both natural and pasteurized pollen that has undergone either spontaneous fermentation or fermentation through bacterial activity by two lactose related bacteria: Lactocoocus lactis and Lactobacillus rhamnosus. The results of this investigation indicate effective beneficial bioactivities and dietary values of various forms of pollen, for the purpose of consumption with the goal of improving of human health, including:

• Fermentation = greater antioxidant activity
• Antioxidant activity of fermented natural pollen > fermented pasteurized pollen
• Antioxidant activity of bacteria fermented pollen > spontaneously fermented pollen
• Fermentation = greater microbial activity; other microbial compounds are also produced by bacteria through the fermentation process
• Fermentation = greater antifungal activity

Small variations and changes in the activities of all evaluated pollen were attributed to the botanical origin of the pollen itself and the type of fermentation process performed. This study concludes these findings with the idea that highlighting the improvement of bioactivities and health-benefitting potentials of bee pollen after fermentation has the potential to “open more applications of bee pollen in the food and pharmaceutical industries.”

* Kaskaniene, V., Adaskevicitue, V., Kaskonas, P., Mickene, R, and Maruska, A. 2020. Antimicrobial and antioxidant activities of natural and fermented bee pollen, Food Bioscience. Full text available ONLINE.

 

What’s the Buzz with ATTTA Podcast Episode 10

Dr Andony Melathopoulos is a researcher and beekeeper with direct ties to eastern Canada.  Having spent time at Nova Scotia’s Dalhousie University (AC campus) while undertaking his doctoral studies, Andony contributed in a positive, and long lasting way to our industry.  Through his research work and enthusiastic teaching Andony left a strong impression on those he met while in Nova Scotia.  Listen to our latest podcast to learn about Andony’s beekeeping journey from eastern Canada to his position on the faculty of Oregon State University.  Find out about his current research related to pollination and honey bee health! You will encounter few beekeepers who are as interested and energetic about honey bees as this months guest, so take a few minutes to meet or reacquaint yourself with this fascinating beekeeper. Listen from your choice of podcast streaming platforms HERE.

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca