Feeding Your Bees... or Feeding Nosema?
- Frank Jeanplong
- 11 hours ago
- 4 min read
New research reveals that nutritional supplements may sometimes help the parasite more than the colony
"Everything we thought we knew about feeding colonies during Nosema infections may need a second look."
Most beekeepers have done it.
When colonies appear weak, pollen may be scarce, or bees are under stress, we reach for protein patties or pollen substitutes. The goal is simple: improve nutrition and help colonies recover.
But what if that extra nutrition also provides exactly what one of the honey bee's most common parasites needs to thrive?
A fascinating new scientific study published in 2026 has produced an unexpected result that could change the way we think about nutritional management during Nosema infections.
Meet the Enemy: Nosema
Nosema (Vairimorpha) is one of the world's most widespread honey bee diseases.
Unlike bacterial or viral infections, Nosema is a microscopic intracellular parasite that invades the cells lining the bee's midgut. As it multiplies, it destroys these cells, reducing digestive efficiency, weakening bees, shortening lifespan, and increasing the number of infectious spores shed throughout the colony.
Those spores spread easily through:
food exchange (trophallaxis)
cleaning behaviour
contaminated comb
flowers visited by infected bees
Once established, Nosema can quietly circulate through an apiary long before obvious symptoms appear.
What Did the Researchers Do?
Scientists from several leading UK universities wanted to answer one simple question:
Does nutritional supplementation help bees fight Nosema—or does it help Nosema grow?
To find out, they reared newly emerged worker bees under laboratory conditions and divided them into four treatment groups:
Healthy bees fed sugar syrup only
Healthy bees fed sugar syrup plus a commercial pollen substitute
Nosema-infected bees fed sugar syrup only
Nosema-infected bees fed sugar syrup plus the same pollen substitute
The bees were monitored for nine days while researchers measured:
✔ survival
✔ infection intensity
✔ total Nosema spores produced per bee.
The Results Surprised Everyone
Instead of helping infected bees recover...
The pollen supplement actually made the infection worse.
The researchers found:
2.6 times more Nosema spores
Infected bees receiving the supplement averaged around 14 million spores per bee, compared with only 5.4 million in bees receiving sugar syrup alone.
Almost 4 times greater risk of death
Mortality increased dramatically when infected bees were given the enriched diet.
Healthy bees were unaffected
Importantly, the pollen supplement caused no increase in mortality in uninfected bees.
So... Why Did Better Nutrition Produce Worse Results?
At first glance, the findings seem completely backwards.
Surely better nutrition should strengthen bees?
The answer lies in understanding how Nosema lives.
Unlike many pathogens, Nosema cannot produce its own energy.
It survives by stealing nutrients from the cells inside the bee's gut.
When infected bees receive additional nutrients, the parasite also gains access to those nutrients.
Rather than starving the parasite, supplementation may actually provide more raw materials for rapid reproduction.
The researchers conclude that nutritional supplementation increased parasite replication rather than improving the bees' ability to eliminate the infection.
Resistance vs Tolerance
One of the most valuable lessons from this study is the difference between resistance and tolerance.
Resistance
The bee suppresses or eliminates the parasite.
Tolerance
The bee continues functioning while carrying a heavy infection.
A tolerant bee may appear reasonably healthy...
...while simultaneously producing millions of Nosema spores.
That means it can become a powerful source of infection for nestmates and even neighbouring colonies.
Sometimes surviving isn't the same as winning.
Does This Mean Pollen Supplements Are Bad?
No.
That is not what this study shows.
The researchers specifically caution against over-interpreting the results.
Their experiment used:
young caged bees
a commercial pollen substitute
a sugar-based diet
controlled laboratory conditions
Previous research has shown that colonies with access to abundant, diverse natural pollen often have stronger immune systems and can better tolerate disease.
Natural pollen contains proteins, lipids, sterols, vitamins, minerals, beneficial microbes, and many plant compounds that artificial diets cannot fully replicate.
The message is not "stop feeding."
The message is:
Nutrition and disease interact in complicated ways.
What This Means for Your Apiary
Although this was a laboratory study rather than a field trial, it offers several practical lessons.
Monitor before you feed
If Nosema is suspected, consider laboratory testing before assuming nutritional supplements alone will solve the problem.
Natural forage still matters
Whenever possible, encourage colonies to access a wide variety of flowering plants rather than relying solely on artificial diets.
Timing may be critical
Providing protein supplements during periods of active Nosema infection may not always produce the desired outcome.
Look beyond colony strength
Strong-looking colonies can still carry heavy Nosema infections and continue spreading spores.
Evidence continues to evolve
Nutrition remains essential for colony health, but future recommendations may become more targeted according to disease status.
Key Takeaways
Better nutrition does not automatically reduce Nosema.
In this study, pollen supplementation significantly increased Nosema spore production.
Infected bees receiving supplements experienced much higher mortality.
Healthy bees showed no negative effects from supplementation.
The findings highlight the importance of distinguishing host resistance from host tolerance.
More field research is needed before changing routine feeding practices.
Final Thoughts
Beekeeping has always balanced science with practical experience.
This study reminds us that the relationship between nutrition and disease is more complex than simply "more food equals healthier bees."
When a parasite depends on the same nutrients as its host, improving nutrition may sometimes benefit both sides of the battle.
For beekeepers, the challenge is no longer simply feeding colonies—it is learning when, how, and under what circumstances nutritional support delivers the greatest benefit.
As research continues, one thing is becoming increasingly clear:
Successful beekeeping isn't just about feeding bees. It's about feeding them wisely.
Find the full-text study here: https://www.sciencedirect.com/science/article/pii/S0022201126001825
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