Gut microbiota of Brazilian stingless bees: dominant members and their localization in different gut regions.

The gut microbiome of eusocial corbiculate bees, which include honeybees, bumblebees, and stingless bees, consists of anciently associated, host-specific bacteria that are vital for bee health. Two symbionts, and , are ubiquitous in honeybees and bumblebees. However, their presence varies in the stingless bee clade (Meliponini), a group with pantropical distribution. They are absent or rare in the diverse genus , indicating a shift in microbiota composition in this lineage. To identify the main members of the microbiota, we combined newly collected and published data from field-collected individuals of several species. Additionally, we identified the localization of the dominant microbiota members within the gut regions of . The dominant microbiota of species includes members of the genera , , , , and . Among these, and dominate in the crop, whereas and other members of the Lactobacillaceae dominate the ventriculus. The ileum lacks or but contains a putative new symbiont close to , as well as strains of , Lactobacillaceae (including ), and . The rectum is dominated by and . In summary, the microbiota is compositionally distinct but shows spatial organization paralleling that of other eusocial corbiculate bees.