β-glucooligosaccharides derived from barley β-glucan promote growth of lactic acid bacteria and enhance nisin Z secretion by Lactococcus lactis

The present study assessed the effects of β-glucooligosaccharides (β-GOS) derived from barley β-glucan on the proliferation and antimicrobial activity of probiotics. All cocci examined in this study and several species of Lactobacilli and bifidobacteria were able to utilize β-GOS as a sole carbon source. In addition, the absence of significant growth of certain pathogens on β-GOS compared to prebiotics fructo-oligosaccharide (FOS) and inulin substrates demonstrates the probiotic specificity of β-GOS metabolism. Increased anti-microbial activities were observed in Lactococcus lactis subsp. lactis, Lactobacillus reuteri, and Pediococcus acidilactici grown in media with β-GOS as the sole carbon source over glucose. β-GOS enabled sustained L. lactis subsp. lactis growth in the exponential phase, resulting in an approximately 25% increase in nisin Z production compared with glucose. These results suggest that β-GOS can selectively modulate probiotic growth in particular cocci, and antimicrobial activity, with important implications for future research in nutrition as well as industrial applications.