Galactooligosaccharides (GOS) are an important class of dietary prebiotics that exert beneficial effects on intestinal microbiota and gut barrier function. In this study, high-purity GOS (HP-GOS) were investigated in vitro and in vivo and confirmed as prebiotic ingredients in rat diet. HP-GOS were successfully produced using a two-step process, enzymatic hydrolysis and fermentation by yeast. They were found to serve as a good substrate and carbon source for supporting the growth of probiotic bacteria more effectively than other commercial GOS. Following administration of 1 % (by mass) of HP-GOS to rats, the growth of Bifidobacterium bifidum and B. longum in the gut increased most rapidly up to 12 h, and thereaft er the increase was slow. Therefore, 1 % HP-GOS was found to be acceptable for the growth of probiotic bacteria. Groups of animals that were orally administered HP-GOS and bifidobacteria during the study, and the group administered HP-GOS during the 2nd (days 13-15) and 4th (days 28-30) period of the study had significantly (p < 0.05) higher numbers of bifidobacteria in faeces than groups receiving a single dose of bifidobacteria. HP-GOS affected the expression of genes encoding glucagon-like peptide-1 (GLP-1) and peptide YY (PYY). There was a significant upregulation of GLP-1 and PYY mRNA with HP-GOS and bifidobacteria intake. We propose that the prebiotic properties of HP-GOS are potentially valuable for the production of functional foods for human consumption.
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Acknowledgements This research was supported by High Value-Added Food Technology Development Program, Ministry of Agriculture, Food and Rural Affairs, Sejong, Republic of Korea.
- Genes encoding GLP-1 and PYY peptides
- High-purity galactooligosaccharides
ASJC Scopus subject areas
- Food Science
- General Chemical Engineering
- Industrial and Manufacturing Engineering