Each bee has its own role and its own flora
Bees are the champions of the division of labor. A study shows how their social status influences the bacteria and fungi of their intestinal flora. Valuable information, both for honey lovers and for the planet.
The life of a honey bee is not a long quiet river, except perhaps for a queen, although reproduction is no easy thing when you have to lay 2,000 eggs per day. Depending on their age and the needs of the colony, a bee will be, successively, a nurse bee, a honey producer, a hive maintenance worker, a guardian, a foraging bee… It is a true model of flexibility. A Korean team has discovered that their intestinal flora adapts to these successive changes in the host social status.
Fungi and bacteria, a close-knit team
Foraging bees are thought to have an intestinal flora that is different from that of nurse bees in terms of fungi. The latter are thought to be colonized by large quantities of yeasts such as Saccharomyces (baker’s yeast group), known in other insects to aid digestion and detoxification of toxic plant compounds. A beneficial dynamic between bacteria and fungi even sometimes operates: in nurse bees, there is thought to be a form of “mutual coexistence” between lactobacilli (probiotic agents common in our yogurts) and yeasts, both present in large numbers in their intestinal flora. This is not an accident: we believe that these yeasts help them digest pollen, a major ingredient —like nectar—of royal jelly. Nurse bees feed this jelly to queen bees in copious quantities, and fashions their intestinal flora in a specific way.
A flora which spares its host
As for foraging bees, their numerous jaunts outside the hive expose them to many microbes: their intestinal bacterial and fungal communities are more diversified than those of nurse bees, confined inside the hive. The flora of foraging bees, which harbors more bacteria capable of using amino acids (the building bricks of proteins), is optimized for their diet: as these bees feed mostly on sugars, their intestinal bacteria do not deprive them of the “fuel” that is essential to perform their social function. And there you have it: a conflict over a resource has been avoided! Naturally, these results cannot be extrapolated to human societies, but they allow for a better knowledge of bees, insects that are as sophisticated as they are indispensable: twenty years after the first warning signals, colony collapse disorder continues to spread everywhere in the world.
Yun JH et al. Social status shapes the bacterial and fungal gut communities of the honey bee. Scientific reports 2018; 8 (2019)