Bees are not only important pollinators, but also hosts to a complex ecosystem of bacteria living in their guts. These bacteria help bees digest their food, fight off infections, and regulate their immune system.
But how do bees feed these beneficial microbes? A recent study by Professor Philipp Engel from the University of Lausanne has revealed that bees synthesize a special food for their gut bacteria, and that this food is crucial for their health and survival.
Bees Make Food for Their Bacteria
Sean Gallup/Getty Images
The study, published in the journal Nature Microbiology, showed that bees produce a substance called bee bread that is rich in sugars, proteins, and lipids. Bee bread is made from pollen and nectar that bees collect from flowers, but it is not the same as honey.
Honey is mainly stored as a food reserve for the winter, while bee bread is consumed daily by the bees and their gut bacteria.
The researchers found that bee bread contains a unique chemical signature that distinguishes it from pollen and nectar. They also discovered that bee bread is essential for the growth and survival of the bacteria in the bee gut.
When they fed bees with artificial diets that lacked bee bread, the bacteria in their guts became less diverse and less abundant, and the bees became more susceptible to diseases and environmental stress.
The researchers analyzed the chemical composition of bee bread and found that it contains fructose, glucose, sucrose, maltose, trehalose, raffinose, stachyose, and mannitol as the main sugars, as well as fatty acids, phospholipids, sterols, and wax esters as the main lipids.
They also detected amino acids, peptides, vitamins, and minerals that are essential for the bacteria
The researchers speculated that bees synthesize bee bread by using enzymes in their saliva and digestive tract to modify the pollen and nectar they ingest.
They also suggested that bees may use microRNAs - small molecules that regulate gene expression - to influence the metabolism of the bacteria and tailor the bee bread to their needs
The findings of the study have important implications for the health and conservation of bees, as well as for human agriculture and biodiversity. Bees are responsible for pollinating about one-third of the world's crops, and their decline in recent years has raised serious concerns. One of the main threats to bees is the use of pesticides, which can harm not only the bees themselves, but also their gut bacteria.
The study suggests that bee bread may help bees cope with pesticide exposure, as it provides nutrients and protection for their gut bacteria. The researchers also propose that bee bread may be used as a probiotic supplement to improve the health and resilience of bees. By understanding how bees feed their gut bacteria, we may be able to help them survive and thrive in a changing world.
The study also sheds light on the evolution and ecology of the bee-bacteria symbiosis, which is one of the most ancient and widespread associations among animals and microbes.
The researchers compared the bee gut bacteria with those of other insects and found that they are highly specialized and adapted to their host.
They also found that the bee gut bacteria are transmitted vertically from mother to offspring, and horizontally among nestmates, creating a shared microbiome within the colony.
The bee gut bacteria are not only beneficial for the bees, but also for the plants they pollinate. The researchers found that the bacteria can produce volatile organic compounds that enhance the scent and attractiveness of the flowers, as well as antibiotics that protect the plants from pathogens.
The bacteria can also influence the gene flow and genetic diversity of the plants by affecting the pollen viability and germination.
The study reveals the remarkable complexity and interdependence of life on Earth, and how a seemingly simple organism like a bee can harbor a sophisticated and dynamic microbial community that affects its own health and the health of the environment.
By learning more about how bees feed their gut bacteria, we may gain new insights into the secrets of nature and the challenges of conservation.
