Can we harness the microbes in bee guts to create stronger bees?

Scholastic Fantastic

Can we harness the microbes in bee guts to create stronger bees?
Jeff Drew illustration

The eight white boxes in a weedy, fenced-off field behind the big red barn at Eastern Washington University are absolutely crawling with life.

Assistant professor Jeni Walke, flanked by undergraduates clad head-to-toe in white protective gear, opens the lid of one of the boxes and pulls out a panel to reveal the contents: honeybees, tens of thousands of them, writhing on the cells of their artificial hives.

She turns over the panel as the bees buzz and scurry about. There — she points to the bee with the big abdomen and the hot pink dot — that's the queen.

Half of these hives are fed on sugar. And half are fed with an artificial nectar treatment. Does that matter? That's what Walke is trying to figure out.

Walke is interested in the honeybee, yes. But she's really interested in much smaller creatures.

For those, you'll want to go smaller. Up the bee's proboscis, through the esophagus, into the bee's thorax and into its stomach and the rest of the digestive tract. That's where you'll find the millions of microscopic creatures that live in the bee's guts, she says.

And the contents of those guts lead to a lot of questions. Like, what do bee guts look like when the bees have been fed artificial nectar instead of the traditional sugar? What about when they have been exposed to pesticides? What about when their hives are infected with parasitic varroa mites (which are the scourge of hives across the country)? What about when they're fed probiotics — the sort of bacterial mixes you'll find advertised in yogurt ads with smiling, laughing women?

Could those probiotics actually protect the bees from pesticides?

"We could potentially supplement the bee-gut microbiome with a beneficial microbe, to protect them from the potential effects," Walke says.

Because at a time where beekeepers are still fighting against the dangers of colony collapse, exactly which creatures are living in each bee's stomachs may mean the difference between death and survival.

Walke didn't start out looking at bees. Her doctoral dissertation was focused on the fungal skin diseases infecting frogs and salamanders. Her attention was drawn to the amphibians' microbiomes — the world of bacteria and other microscopic organisms — that were living on the amphibians' skins. The right microbiome seemed to actually protect against the skin diseases.

With bee populations struggling as well, applying the study of microbiotics to the hive seemed promising.

"Native bees are definitely experiencing declines. Managed honeybee hives in general are still experiencing losses," Walke says. "I think, last I looked, a couple years ago, 30 or 40 percent of hives are lost each year."

There are a lot of reasons for the losses. But that's one of the reasons why this research is so important. It could, down the road, save bee lives.

Fortunately, getting the contents of a bee's digestive system is easy.

"It's actually a very convenient dissection method," Walke says. No scalpel necessary.

All Walke has to do is grab the stinger of the dead honeybee with forceps and pull. The stinger pulls the guts of the bee with it. Then, using what amounts to a tiny blender, she grinds up the guts in a sterile solution. Then she dilutes the slurry mixture a couple of times.

From here, her team can squirt an enzyme into a test tube that amplifies the DNA in the slurry, so it's possible to analyze. And that's when they start running some high-tech tests.

"You look at the DNA sequences of all of the different bacteria in there," Walke says. "There are special programs that can identify which bacteria are more abundant in one treatment or another."

In other words, Walke and her team can get a readout of the approximate mix of the microbes swimming around a bee's digestive system. And then she can see how that mix changes if you change what the bee eats.

Place a jar of sugar or nectar spiked with a probiotic in the hive, for example, and you can begin to change what the bees are like internally.

One particular aspect of bee hygiene makes her job easier.

"They basically eat each other's spit and poop," Walke says. The gut biome of a few bees in the hive can spread to the others.

They can also use the bee-gut slurry in another way: spreading it into a petri dish and growing cultures. Ultimately, that bacteria can be used to create a nectar or sugar probiotic cocktail that she can feed to the bees, influencing their microbiomes.

In fact, there's already a product being marketed to beekeepers called "SuperDFM-Honeybee" from Strong Microbials. Strong Microbials brags that its substance "helps boost immunity," "supports gut health" and is an "excellent digestive aid."

They're the sort of health claims you might find at a Portland smoothie stand, but, you know, for bees. It doesn't seem to all be hype, either.

"I've actually tested that probiotic," Walke says. "There might be something with that mitigating the effects of the pesticides."

That research is preliminary, she cautions. Science has to be replicated. But in the meantime, there are a whole lot of bees to study. Everywhere.

"If you look at my car seat, there are squished bees," Walke says. "Fortunately, when I sat down on them, I didn't feel stinging." ♦

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