The abilities to survive winter and to adapt to major food changes are key traits that have enabled successful range expansion of the honey bees from the tropic to temperate climate. Our results highlighted a new possibility that gut bacteria may have played an important role in host survival of the severe winter condition.

Honey and bumble bees are import pollinators, playing significant roles in the agricultural industry and maintaining the bio-ecosystem balance. Recently, it was found that the bees harbor a simple, yet specific gut microbiota. The normal bee gut microbiota makes essential contributions to host growth, endocrine signaling, and pathogen resistance. With the development of high through-put sequencing technology, researchers can now quickly identify the gut community structure for a low cost. This is helpful for biodiversity, conservation and bee health studies. However, the currently-used 16S rRNA databases are not specific enough to classify the bee gut microbiota properly. Many of the specific bacteria that enrich the gut of Apis cerana are in the genus Apibacter. Here, we isolated Apibacter species from A. cerana collected in five provinces of China, and added them to the current SILVA database. We also curated the nomenclature of some existing sequences and reclassified them in the updated database. Based on the analysis of the 16S rRNA sequencing data from one A. cerana and one Apis mellifera sample, our Bee Gut Microbiota-Database (BGM-Db) offers a more accurate classification of bee gut microbiota at a higher resolution than either the