Structural characteristics and functional properties of a fucose containing prebiotic exopolysaccharide from Bifidobacterium breve NCIM 5671

Aim: To evaluate the structure and functions of capsular exopolysaccharide (CPS) from Bifidobacterium breve NCIM 5671.
Methods and results: A CPS produced by the probiotic bacteria B. breve NCIM 5671 was isolated and subjected to characterization through GC
analysis, which indicated the presence of rhamnose, fucose, galactose, and glucose in a molar ratio of 3:1:5:3. The average molecular weight of
the CPS was determined to be ∼8.5 × 105 Da. Further, NMR analysis revealed the probable CPS structure to be composed of major branched
tetra- and penta-saccharide units alternately repeating and having both α- and β-configuration sugar residues. CPS displayed an encouraging
prebiotic score for some of the studied probiotic bacteria. Compared to standard inulin, CPS showed better resistance to digestibility against
human GI tract in vitro. DPPH, total antioxidant, and ferric reducing assays carried out for CPS displayed decent antioxidant activity too.
Conclusion: This study indicates that the CPS from B. breve NCIM 5671 has the potential to be utilized as a prebiotic food supplement. It is a
high-molecular-weight (∼8.5 × 105 Da) capsular heteropolysaccharide containing rhamnose, fucose, galactose, and glucose.