Investigation of dietary fructooligosaccharides from different production methods: Interpreting the impact of compositions on probiotic metabolism and growth

Fructooligosaccharides (FOS) are common prebiotics in the food industry. The two major methods employed in commercial production afford FOS in different compositions. To evaluate the exact impact of chemical compositions of FOS on probiotics, FOS are essayed in a “mixture” and a “pure” form. Probiotics show distinctively different preferences for the separated FOS. The metabolic intermediates and kinetics of the isolated FOS were investigated, indicating the crucial role of the structure and degree of polymerization (DP) of the FOS compositions. Extracellular enzymes preferentially degrade long-chained FOS for facilitating the uptake, whereas hydrolysis rates do not always positively determine the bacteria growth. Bifidobacterium strains have a highly selective and specific utilization pattern towards trisaccharide 1-kestose (GF 2 ), which contributes to its best growth promotion effect. In conclusion, the metabolic pathways and kinetics, the growth promotion effect of FOS on probiotics are directly related to the structures and the DP of the components.