Niche partitioning facilitates coexistence of closely related honey bee gut bacteria

Abstract

Ecological processes underlying bacterial coexistence in the gut are not well understood. Here, we disentangled the effect of the host and the diet on the coexistence of four closely related Lactobacillus species colonizing the honey bee gut. We serially passaged the four species through gnotobiotic bees and in liquid cultures in the presence of either pollen (bee diet) or simple sugars. Although the four species engaged in negative interactions, they were able to stably coexist, both in vivo and in vitro. However, coexistence was only possible in the presence of pollen, and not in simple sugars, independent of the environment. Using metatranscriptomics and metabolomics, we found that the four species utilize different pollen-derived carbohydrate substrates indicating resource partitioning as the basis of coexistence. Our results show that despite longstanding host association, gut bacterial interactions can be recapitulated in vitro providing insights about bacterial coexistence when combined with in vivo experiments.

Species divergence in gut-restricted bacteria of social bees

“…In contrast, G. apis populations are enriched with only the transporters and the genes related to pectin-derived galacturonide metabolism. Potentially, they utilize different substrates from pollen and therefore can coexist in the same host, as documented for Lactobacillus species in bee guts ( 45 ).…”

Global Composition of the Bacteriophage Community in Honey Bees

“…It was recently shown that closely related strains of Lactobacillus nr. melliventris coexist in the honey bee gut through niche partitioning of pollen metabolism ( 64 ). Whether or not phages specialize on these functionally divergent bacteria and if phage host range evolution affects these bacterial communities remain interesting questions.…”

Distinct Roles of Honeybee Gut Bacteria on Host Metabolism and Neurological Processes

“…Recently, the causal roles of honeybee gut bacteria in host nutrition, weight gain, and endocrine signaling have been extensively studied ( 15 ), and these studies benefit from the availability of microbiota-free (MF) bees ( 9 , 16 ). In particular, Gilliamella , Bifidobacterium , and Lactobacillus Firm5 can degrade diet polysaccharides in the honeybee gut, which might assist pollen perforation, resulting in the release of nutrient-rich content ( 17 – 19 ). In addition, interspecies interactions facilitate carbohydrate metabolism and amino acid synthesis, thus benefiting the host ( 18 , 20 ).…”