title: Evaluation of Prebiotic Effects of High-Purity Galactooligosaccharidesin vitroandin vivo.
abstract: 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 investigatedin vitroandin vivoand 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 ofBifidobacterium bifidumandB. longumin the gut increased most rapidly up to 12 h, and thereafter 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.
authors.affiliation: Department of Public Health Sciences, Graduate School, Korea University, Seoul 07249, Republic of Korea.
authors.forename: Ki Bae
authors.initials: KB
authors.lastname: Hong
authors.affiliation: Neo Cremar Co. Ltd., Seoul 05836, Republic of Korea.
authors.forename: Jae Hwan
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Neo Cremar Co. Ltd., Seoul 05836, Republic of Korea.
authors.forename: Hyuk Kon
authors.initials: HK
authors.lastname: Kwon
authors.affiliation: Department of Public Health Sciences, Graduate School, Korea University, Seoul 07249, Republic of Korea.
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Han
authors.affiliation: Dongguk University, Research Institute of Biotechnology, Goyang 10326, Republic of Korea.
authors.forename: Yooheon
authors.initials: Y
authors.lastname: Park
authors.affiliation: Department of Public Health Sciences, Graduate School, Korea University, Seoul 07249, Republic of Korea.
authors.forename: Hyung Joo
authors.initials: HJ
authors.lastname: Suh
keywords: bifidobacteria; genes encoding GLP-1 and PYY peptides; high-purity galactooligosaccharides