Bee pollen is a nutrient-rich food that meets the nutritional requirements of honey bees and supports human health. This study aimed to provide nutritive composition data for 11 popular bee pollen samples (Brassica napus (Bn), Bidens pilosa var. radiata (Bp), Camellia sinensis (Cs), Fraxinus griffithii (Fg), Prunus mume (Pm), Rhus chinensis var. roxburghii (Rc), Bombax ceiba (Bc), Hylocereus costaricensis (Hc), Liquidambar formosana (Lf), Nelumbo nucifera (Nn), and Zea mays (Zm)) in Taiwan for the global bee pollen database. Macronutrients, such as carbohydrates, proteins, and lipids, were analyzed, which revealed that Bp had the highest carbohydrate content of 78.8 g/100 g dry mass, Bc had the highest protein content of 32.2 g/100 g dry mass, and Hc had the highest lipid content of 8.8 g/100 g dry mass. Only the bee pollen Hc completely met the minimum requirements of essential amino acids for bees and humans, and the other bee pollen samples contained at least 1–3 different limiting essential amino acids, i.e., methionine, tryptophan, histidine, valine, and isoleucine. Regarding the fatty acid profile of bee pollen samples, palmitic acid (C_16:0), stearic acid (C_18:0), oleic acid (C_18:1), linoleic acid (C_18:2), and linolenic acid (C_18:3) were predominant fatty acids that accounted for 66.0–97.4% of total fatty acids. These data serve as an indicator of the nutritional quality and value of the 11 bee pollen samples.

Aureobasidium melanogenum has been used as an animal feed additive for improving thehealth of pets, however, it has not yet been applied in honey bees. Here, a fungal strain CK-CsC isolated from bee bread pollen, was identified as A. melanogenum. Following characterizing CK-CsC fermentation broth, the 4-days fermentation broth (SYM medium or bee pollen) of the CK-CsC was used to feed newly emerged adult honey bees in cages under laboratory-controlled conditions for analysis of survival, gene expression of nutrient and antibacterial peptide, and gut microbiota of honey bees. It was found that the CK–CsC fermentation broth (SYM medium or bee pollen) is nontoxic to honey bees, and can regularly increase nutrient gene expression of honey bees. However, significant mortality of bees was observed after bees were fed on the supernatant liquid of the fermentation broth. Notably, this mortality can be lowered by the simultaneous consumption of bee pollen. The honey bees that were fed bee pollen exhibited more γ-Proteobacteria, Bacteriodetes, and Actinobacteria in their gut flora than did the honey bees fed only crude supernatant liquid extract. These findings indicate that A. melanogenum CK–CsC has high potential as a bee probiotic when it was fermented with bee pollen.