Development of an oral immunoadjuvant from cheonggukjang that is efficacious for both mucosal and systemic immunity

Immunological properties of a 50% ethanol/aqueous extract of cheonggukjang (CGJ), a fermented soybean product, were investigated as a potent, orallyavailable, and cost-effective immunoadjuvant. Different from cholera toxin, a widely used experimental oral adjuvant with effects limited to mucosal immunity in the gut, oraladministration of the CGJ extract had positive effects on both mucosal and systemic immunity. Administration of keyhole limpet hemocyanin (KLH) with the CGJ extract resulted in hyper-production of KLH-specific IgA in the gut and KLH-specific IgG in the serum. Oral-administration of the CGJ extract resulted in promotion of both Th1 and Th2 immune responses, thus eliminating concerns over an imbalanced Th1 and Th2 immune bias that is often observed upon administration of other commonly used immunoadjuvants. Ethanol/aqueous extraction of CGJ resulted in enrichment of polyphenolic compounds, including flavonoids, providing a potential extra health benefit. © 2014 The Korean Society of Food Science and Technology and Springer Science+Business Media Dordrecht.