This study measured the proliferative activity of malto-oligosaccharide (MOS) as a prebiotic against Bifidobacteria, resistance to digestion in vitro, and changes during in vitro fermentation by human fecal microorganisms. It consisted of 21.74%, 18.84%, and 11.76% of maltotriose, maltotetraose, and maltopentaose produced by amylase (HATT), respectively. When 1% of MOS was added to a modified PYF medium as the carbon source, proliferation of Bifidobacterium breve was increased significantly. During the in vitro digestion test, MOS was partially degraded by intestinal enzymes. Fermentation characteristics by human fecal microorganisms were evaluated by adding 1% galacto-oligosaccharide (GOS), as well as 1% and 2% MOS as carbon sources to the basal medium, respectively. In comparison with the addition of 1% of MOS and GOS, the total short chain fatty acid (SCFA) content increased over time when 2% of MOS was added. The species diversity and richness of intestinal microbiota increased significantly with 2% MOS compared to those with 1% GOS. In addition, the 2% addition of MOS reduced intestinal pathobiont microorganisms and increased commensal microorganisms including Bifidobacterium genus. Collectively, MOS produced by amylase increased the SCFA production and enhanced the growth of beneficial bacteria during in vitro fermentation by human fecal microbiota.
Keywords: SCFA; in vitro fermentation; malto-oligosaccharide; prebiotics.