Prebiotic Effects of α- and β-Galactooligosaccharides: The Structure-Function Relation

Abstract

Oligosaccharides containing galactosyl moieties belong to two main groups: raffinose family oligosaccharides (RFO, α-GOS) and lactose-type β-galactooligosaccharides (β-GOS), both well-known for their prebiotic effect. The present review investigates the vast amounts of recent research on the structures of GOS and their beneficial impact. It focuses on the molecular interactions between GOS and probiotics in vitro and in vivo, the enzymology of the processes, and the genetic prerequisites for the synthesis and degradation of GOS by probiotic bacteria. The preferences of probiotic strains belonging to the Bifidobacterium and Lactobacillus genera are elucidated to form and degrade GOS of a certain length, structure, and linkages between monomers. A brief overview of the industrial production of β-GOS by natural and recombinant strains included the methods and production efficiency evaluation.