CONCLUSION
Honey bees are challenged continuously by environmental and agricultural
factors that alter colony demography. Our results demonstrate that the
social structure of honeybee colonies affects composition of the gut
microbiota. Behavioral differences are associated with internal damage
from reactive oxygen species, and changes in gene expression that rely
on nutritional state and task. Precocious foragers accrue oxidative
damage as a result of intense foraging activity experienced by a
physiologically deficient adult worker. The colony-level cost of
precocious foraging is extreme and one of many altruistic qualities
inherent to social insects. The physiological demands of foraging are
best met by older workers that have transitioned to foraging following
extended development within the hive. In a healthy colony, the
characteristic transition from nurse to forager results in less
physiological stress. Consistent with this hypothesis, the ratio
abundance of keystone ileum species S. alvi and G. apicolais refined with an extended nursing period, setting the stage for
long-lived foragers. As workers age, we propose that the midgut becomes
a niche for rapid microbial colonization, with consequences for both
individual and colony survival.