Probiotics may protect bees against fatal disease

Special to Western NewsResearchers at Western and Lawson Health Research Institute recently published a study, Novel probiotic approach to counter Paenibacillus larvae infection in honey bees, exploring the possibilities of probiotics in saving honey bee colonies from collapse.

Microorganisms best known for promoting gut health in humans may be the key to saving honey bee colonies from collapse, according to a novel discovery by Western and Lawson Health Research Institute researchers.

“Probiotics aren’t just for humans,” said Gregor Reid, a Schulich School of Medicine & Dentistry professor and Endowed Chair in Human Microbiome and Probiotics at Lawson. “Our idea was that if you could use beneficial microbes to stimulate the immune response or attack the pathogens that are infecting the hives, then maybe we can help save the bees.”

The study, Novel probiotic approach to counter Paenibacillus larvae infection in honey bees, was published Tuesday in The ISME Journal.

Honey bees are an important part of the cultural and economic landscape because of their role in food production both through pollination of crops and honey production. However, the world’s bee population is being threatened by the spread of viruses and bacteria that infect the hives.

The team’s previous work in a fruit-fly model suggested that the wide-use of pesticides reduces bees’ immunity and their ability to fight back against these harmful pathogens.

With that in mind, Western and Lawson researchers combined their expertise in probiotics and bee biology to supplement honey bee food with probiotics in the form a BioPatty, in their experimental apiaries. The aim was to see what effect probiotics would have on honey bee health.

During their experiment, the hives became inadvertently infected with American Foulbrood, a common hive disease produced by the bacteria P. larvae, which would typically cause the bees to die.

“Bee colonies are really interesting little microcosms of biology. There are lots of individuals bees, but they are all genetically related and they are living in a close confined space,” Biology professor Graham Thompson said. “They are all very susceptible to contagious disease and they are demographically disposed to outbreaks.”

The team found that in the bee hives treated with probiotics, the pathogen load was reduced by 99 per cent, and the survival-rate of the bees increased significantly. When they examined the bees in the lab, they also found that there was increased immunity against the bacteria that causes American Foulbrood in the bees treated with the probiotics.

“The results from our study demonstrated that probiotic supplementation could increase the expression of a gene called Defensin-1 – a key antimicrobial peptide shown to play a pivotal role in honey bee defense against P. larvae infection,” said Schulich PhD Candidate Brendan Daisley, who served as lead author on the paper. “Alongside these findings, we also observed an increase in pathogen clearance and overall survival of honey bee larvae.”

Crystal Mackay // Special to Western NewsSchulich PhD Candidate Brendan Daisley, along with Western and Lawson Health Research Institute colleagues, combined their expertise in probiotics and bee biology to supplement honey bee food with probiotics in the form a BioPatty, in their experimental apiaries. The aim was to see what effect probiotics would have on honey bee health.

Additionally, the bees given BioPatty but no probiotic were the most susceptible, even more so than bees given nothing at all. The research team says this suggests there may be a negative outcome to the common practise of supplementing bee colonies with extra food as it could stimulate the pathogens to proliferate.

“Long term, we hope to add a viable, practical and available treatment alternative to chemicals and antibiotics that beekeepers can readily adopt into their bee-keeping habits to help prevent colony collapse,” Thompson said.

Through funding from the Natural Sciences and Engineering Research Council of Canada (NSERC), Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) and the Weston Foundation, the group are currently testing the BioPatties in hives in both California, where the multi-billion dollar almond industry relies on honey bees, and on rooftops in downtown Detroit.