Captive-rearing changes the gut microbiota of the bumblebee <i>Bombus lantschouensis</i> native to China

Bumblebees play crucial roles as pollinators in both natural agricultural and ecological systems. Their health and overall fitness are significantly affected by the gut microbiota, which can maintain intestinal homeostasis in hosts by regulating their nutritional metabolism. However, information about the diversity of the gut microbiota and related functional changes during artificial rearing of native species is currently limited. This study investigated the dynamic remodeling of gut microbiota in the Chinese native bumblebee <i>Bombus lantschouensis</i> under captive rearing, supported by 16S rRNA amplicon sequencing of bacterial DNA. The typical microbial community composition of the bumblebee was detected in the gut of wild <i>B. lantschouensis</i>, with species of genus <i>Gilliamella</i> and <i>Snodgrassella</i> identified as the dominant strains. Conversely, the microbiota of the captive-reared group showed increased diversity and decreased abundance of certain species of microorganisms. The populations of <i>Bifidobacterium</i>, <i>Saccharibacter</i>, and <i>Lactobacillus</i>, including Firm-4 and Firm-5, were dramatically increased after captive-rearing and became the dominant bacteria, while <i>Gilliamella</i> and <i>Snodgrassella</i> were strikingly reduced. Notably, this study found that pathogenic bacteria appeared in the intestines of wild-caught <i>B. lantschouensis</i> and disappeared when the host was reared under captive conditions. This study shows microbial community changes in bumblebees and facilitates the study of physiological metabolism in the commercial rearing of insects.