Development of hypoallergenic galacto-oligosaccharides on the basis of allergen analysis.

Galacto-oligosaccharides (GOSs) are recognized as prebiotics beneficial to human health through their abilities to modulate gut microbiota. On the other hand, it has been reported that immediate allergic reactions are caused by a GOS product (Bc-GOS) produced by treating lactose with β-galactosidase derived from Bacillus circulans. The objective of this study was to create a safer GOS product that is less likely to cause GOS-induced allergy (GOS-AL). First, we identified two derivatives of tetrasaccharide sugar chains in Bc-GOS as the factors responsible for GOS-AL by histamine release test (HRT) using blood samples obtained from two GOS-AL patients. Through our search for non-allergic GOS, we developed a new GOS product, SK-GOS, which was produced by catalyzing lactose with β-galactosidase derived from Sporobolomyces singularis and Kluyveromyces lactis. We regard it as a hypoallergic and safe GOS product that does not cause GOS-AL.