The role of mucin and oligosaccharides via cross-feeding activities by Bifidobacterium: A review

Bifidobacteria are one genus of low-abundance gut commensals that are often associated with host health-promoting effects. Bifidobacteria can degrade various dietary fibers (i.e., galactooligosaccharides, fructooligosaccharides, inulin), and are reported as one of the few gut-dwelling microbes that can utilize host-derived carbohydrates (mucin and human milk oligosaccharides). Previous studies have noted that the superior carbohydrate-metabolizing abilities of bifidobacteria facilitate the intestinal colonization of this genus and also benefit other gut symbionts, in particular butyrate-producing bacteria, via cooperative metabolic interactions. Given that such cross-feeding activities of bifidobacteria on mucin and oligosaccharides have not been systematically summarized, here we review the carbohydrate-degrading capabilities of various bifidobacterial strains that were identified in vitro experiments, the core enzymes involved in the degradation mechanisms, and social behavior between bifidobacteria and other intestinal microbes, as well as among species-specific bifidobacterial strains. The purpose of this review is to enhance our understanding of the interactions of prebiotics and probiotics, which sheds new light on the future use of oligosaccharides and bifidobacteria for nutritional intervention or clinical application. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Bifidobacteria, a low-abundance gut commensal genus, have superior carbohydrate-metabolizing abilities that benefit other gut symbionts, particularly butyrate-producing bacteria. Through cooperative metabolic interactions and cross-feeding activities on mucin and oligosaccharides, bifidobacteria play a crucial role in the intestinal ecosystem. Studying the social behavior between bifidobacteria and other intestinal microbes sheds light on the future use of oligosaccharides and bifidobacteria for nutritional interventions or clinical applications.