Bifidobacterium carbohydrases‐their role in breakdown and synthesis of (potential) prebiotics

Abstract

There is an increasing interest to positively influence the human intestinal microbiota through the diet by the use of prebiotics and/or probiotics. It is anticipated that this will balance the microbial composition in the gastrointestinal tract in favor of health promoting genera such as Bifidobacterium and Lactobacillus. Carbohydrates like non-digestible oligosaccharides are potential prebiotics. To understand how these bacteria can grow on these carbon sources, knowledge of the carbohydrate-modifying enzymes is needed. Little is known about the carbohydrate-modifying enzymes of bifidobacteria. The genome sequence of Bifidobacterium adolescentis and Bifidobacterium longum biotype longum has been completed and it was observed that for B. longum biotype longum more than 8% of the annotated genes were involved in carbohydrate metabolism. In addition more sequence data of individual carbohydrases from other Bifidobacterium spp. became available. Besides the degradation of (potential) prebiotics by bifidobacterial glycoside hydrolases, we will focus in this review on the possibilities to produce new classes of non-digestible oligosaccharides by showing the presence and (transglycosylation) activity of the most important carbohydrate modifying enzymes in bifidobacteria. Approaches to use and improve carbohydrate-modifying enzymes in prebiotic design will be discussed.

Carbohydrate metabolism in Bifidobacteria

“…Only a minority of the sugars utilized by bifidobacteria are believed to be internalized via a PEP-PTS [19,75], while uptake of most of the remaining, more complex sugars is possibly facilitated through the use of specific ABC transporters [124]. Following internalization such carbohydrates can then be hydrolysed, phosphorylated, deacetylated and/or transglycosylated by dedicated intracellular enzymes (Table 6) [142,151]. Analysis of recently sequenced bifidobacterial genomes disclosed intriguing insights into the relationship between these bacteria and their human host.…”

“…There are relatively few publications that review characterized carbohydrate hydrolases of Bifidobacterium sp. [141,142,145]. Therefore, this review will focus on the currently available knowledge on bifidobacterial carbohydrate metabolism, covering the utilization of monosaccharides, disaccharides, oligosaccharides and polysaccharides.…”

Effect of Overgrowth or Decrease in Gut Microbiota on Health and Disease

“…The increase in number of these genera could cause abscess formation, sepsis, inflammatory bowel disease (IBD), Crohn's disease, toxicity, infection and malnutrition (5)(6)(7)(8). However, a decrease in the number of these bacteria is accompanied by allergies in infants, inflammation, malabsorption syndrome, carbohydrate/fiber intolerance, atopic eczema, and IBD.…”

Molecular Cloning and Characterization of a β-l-Arabinobiosidase in Bifidobacterium longum That Belongs to a Novel Glycoside Hydrolase Family

“…Bifidobacteria are strictly anaerobic lactic acid-producing bacteria that are common in the lower intestinal microflora of human and animals. Because simple digestive sugars are preferentially absorbed in the upper intestinal tract, these bacteria survive in the lower intestinal tract by using glycoside hydrolases to cleave complex oligosaccharides (22). For example, B. longum NCC2705 encodes 14 members of the GH43 and GH51 families including ␣-L-arabinofuranosidases (23), and monomeric carbohydrates, such as L-arabinose, induce ␣-Larabinofuranosidase activity in B. longum NIZO B667 (24).…”