Prospects for probiotics in social bees

Abstract

Social corbiculate bees are major pollinators. They have characteristic bacterial microbiomes associated with their hives and their guts. In honeybees and bumblebees, worker guts contain a microbiome composed of distinctive bacterial taxa shown to benefit hosts. These benefits include stimulating immune and metabolic pathways, digesting or detoxifying food, and defending against pathogens and parasites. Stressors including toxins and poor nutrition disrupt the microbiome and increase susceptibility to opportunistic pathogens. Administering probiotic bacterial strains may improve the health of individual bees and of hives, and several commercial probiotics are available for bees. However, evidence for probiotic benefits is lacking or mixed. Most bacterial species used in commercial probiotics are not native to bee guts. We present new experimental results showing that cultured strains of native bee gut bacteria colonize robustly while bacteria in a commercial probiotic do not establish in bee guts. A defined community of native bee gut bacteria resembles unperturbed native gut communities in its activation of genes for immunity and metabolism in worker bees. Although many questions remain unanswered, the development of natural probiotics for honeybees, or for commercially managed bumblebees, is a promising direction for protecting the health of managed bee colonies. This article is part of the theme issue ‘Natural processes influencing pollinator health: from chemistry to landscapes’.

A short exposure to a semi-natural habitat alleviates the honey bee hive microbial imbalance caused by agricultural stress

“…Dysbiosis of the intestinal flora can compromise honey bee resilience and cause disease onset, while positive reinforcement induces recovery of beneficial microbial profiles and strengthens host health 6 . Recuperation of the core microbiota could be achieved through probiotic supplementation of core gut bacteria 21 . However, there is no consensus on what causes gut microbiota dysbiosis, its regulation and recovery, and how it affects (and is affected by) other hive microbial communities.…”

Natural processes influencing pollinator health

“…Motta et al . [ 72 ] review the existing literature on these health benefits derived from the bacterial microbiome of social corbiculate bees (honeybees, bumblebees, stingless bees), and present new data on the potential of inoculating honeybees with probiotic bacteria as a way to improve their health. They highlight that stressors like antibiotics or poor diet may disrupt the bee microbiome, and lead to increased disease susceptibility.…”

“…Beneficial microbial symbionts of pollinators can improve pollinator health through digesting or detoxifying diet components, defending against parasites, or stimulating immune and metabolic pathways of the host. Motta et al [72] review the existing literature on these health benefits derived from the bacterial microbiome of social corbiculate bees (honeybees, bumblebees, stingless bees), and present new data on the potential of inoculating honeybees with probiotic bacteria as a way to improve their health. They highlight that stressors like antibiotics or poor diet may disrupt the bee microbiome, and lead to increased disease susceptibility.…”

“…Administering probiotic bacteria to bees has the potential to restore health-promoting microbiomes, but experimental evidence for the promise of this approach is largely missing. Motta et al [72] experimentally show that commercially available probiotics with bacteria that are not natively found in the honeybee gut fail to colonize honeybees, while cultured native bacterial strain colonies efficiently and induce the activation of immune and metabolism genes. This suggests existing probiotics may have limited or no benefits for honeybees, but future probiotic research in bees should focus on using bacterial strains with beneficial health effects naturally found in bees.…”

Cooperative host-microbe metabolism of a plant toxin in bees

“…Whether amygdalin is fully processed by bee GHs (21) or by pollen-derived GHs that bees ingest (23) is unknown. Another possibility is that the bee gut microbiota (24)(25)(26) contributes to amygdalin degradation, as suggested by the vast arsenal of GHs produced by the dominant bee gut bacterial species (27,28). Interestingly, amygdalin itself does not show antibacterial effects in vitro, and the honey bee gut microbiota appears not to be significantly affected by amygdalin exposure (29).…”