Non-digestible long chain beta-glucans as novel prebiotics

As our understanding of host gut microbiome increases, research interests in the fields of prebiotics, probiotics and synbiotics are growing rapidly. Currently, the majority of prebiotics in the markets are derived from non-digestible oligosaccharides. Very few investigations have been focused on non-digestible long chain complex carbohydrates/polysaccharides for their potential as novel prebiotics. One of the reasons behind this is the unavailability of non-digestible polysaccharides that can fulfill the criteria as prebiotics. Beta-glucans that exist as non-digestible polysaccharides derived from different food sources have demonstrated not only health promoting effects, but also the potential as a novel source of prebiotics. This review commences with the current trends in the research fields of prebiotics, probiotics and synbiotics. This is followed by a discussion of the potential of long chain beta-glucans to serve as novel prebiotics based on current knowledge on their sources, preparation, fermentation characteristics, and the plausible mechanisms involved in their utilization. Some future research directions with emphasis on new approaches using molecular biology, genetics and genomics are also discussed.