Pollen beebreads as a source of probiotics: a metagenomic and biochemical characterization

BACKGROUND Pollen beebread, a fermented pollen stored in honeycombs, is a crucial food source for honey bees and holds promise as a nutraceutical for humans. This study investigated the nutritional composition, antioxidant properties, and microbiota of beebread derived from three major floral sources in Taiwan: rapeseed ( Brassica napus , Bn), beggartick ( Bidens pilosa var. radiata , Bp), and tea tree ( Camellia sinensis , Cs). RESULTS Beebread from different floral sources exhibited significant differences in protein content (up to ~140 mg bovine serum albumin equivalents (BSAE) g −1 in Bn beebread vs. ~105 mg BSAE g −1 in Bp and Cs beebread), phenolic content (up to ~30 mg gallic acid equivalents g −1 in Bn beebread), flavonoid content (up to ~45 mg quercetin equivalents g −1 in Bn beebread), and antioxidant activity (up to ~130 μmol Trolox equivalents g −1 in Bn beebread). A metagenomic analysis revealed distinct microbiota across samples, with differences in alpha diversity: Bn beebread exhibited higher species richness, whereas Cs beebread exhibited greater evenness. Firmicutes were the dominant phylum in Bn and Bp beebread (average relative abundances of 57.5% and 57.7%, respectively), whereas Proteobacteria predominated in Cs beebread (58.5%). Lactobacillus was the most abundant genus, with average relative abundances of 52.8% and 51.5%, respectively, in Bp and Bn beebread samples. CONCLUSION These findings highlight the influence of floral origin on the nutritional and microbial profiles of beebread and support its potential as a source of beneficial microbes and nutrients.