Bacterial diversity associated with <i>Apis cerana</i> <i>himalaya</i> Smith 1991 across altitudinal gradients in the eastern hill region of India

Bacterial communities associated with host insects regulate physiology through changes in immune-metabolic responses and processes that function in tandem to shape the composition of the microbiota. The Himalayan honey bee, <i>Apis cerana himalaya</i> is an important pollinator species in the north eastern hill (NEH) region of India. The 16S rRNA gene amplicon sequencing was carried out to investigate the composition and diversity of gut bacterial communities of <i>A. cerana</i> <i>himalaya</i> from four different altitudinal gradient geographical regions of NEH. The investigation revealed that an altitude of 1577 m mean sea level (Kamjong) workers <i>A. cerana</i> <i>himalaya</i> show the highest number (1957) of unique Amplicon Sequence Variants (ASVs), while 1129 unique ASVs in the lowest altitudinal region (Imphal West), indicating a highly specialized bacterial community shaped by the altitude of the geographical region. Phylum Proteobacteria was highest in high altitude (Shirui) (58.99%), and lowest in mid-altitude (Kamjong) (25.77%), showing significant variation in different altitudinal locations. Principal coordinates analysis indicated clear altitudinal differentiation in microbial profiles, displaying the most distinct community structure. This research highlights the critical impact of altitudinal locations and prevailing environmental conditions on the gut microbiota of <i>A. cerana</i> <i>himalaya</i>. Further research is required for a deeper understanding of the nature of this altitudinal relationship of bacterial composition.