Chain conformation, physicochemical properties of fucosylated chondroitin sulfate from sea cucumber Stichopus chloronotus and its in vitro fermentation by human gut microbiota

Abstract

This study investigated the chain conformation, physicochemical properties of fucosylated chondroitin sulfate from Stichopus chloronotus (fCS-Sc) using HPSEC-MALLS and worm-like cylinder model methods and its impact on human gut microbiota by 16s RNA gene sequencing. The results indicated that fCS-Sc adopted rigid rods chain conformation in PBS based on chain conformational parameters α_η (1.11) and α_h (0.70). Stiffness parameters deduced from worm-like cylinder model suggested that fCS-Sc exhibited as stiff chains. The congo red assay indicated a single-helical structure. fCS-Sc demonstrated a negative zeta-potentials in a wide pH ranges and good thermal stability. Besides, fCS-Sc could modulate the community structure of gut microbiota by elevating the absolute abundance of microbiota, increasing the beneficial bacterium Megamonas, Bacteroides, Fusobacterium, Parabacteroides, Prevotella, Faecalibacterium, suppressing pathogenic microorganism and promoting the short-chain fatty acids production. The present studies improved the understanding of the spatial structures of fCSs and its application as prebiotics.

Keywords: Chain conformation; Fucosylated chondroitin sulfate; Gut microbiota; In vitro fermentation; Physicochemical properties; Stichopus chloronotus.