Interaction of sulfated polysaccharides with intestinal Bacteroidales plays an important role in its biological activities

The bioactivities of sulfated polysaccharides have shown to be associated with the gut microbiota, but the underlying mechanisms remain unclear. In this study, the effect of sulfated polysaccharides from pacific abalone (AGSP) on the human gut microbiota was analyzed via an in vitro fermentation model. The results revealed that AGSP altered the overall structure of the gut microbiota and increased relative abundances of some Bacteroidales members, implying that intestinal Bacteroidales can play important roles in the bioactivities of AGSP. To elucidate the underlying mechanisms, some species from the Bacteroides and Parabacteroides within Bacteroidales were isolated, and their characteristics on AGSP utilization were analyzed. It showed that AGSP utilization by intestinal Bacteroidales was species-dependent, and some species that liberated AGSP breakdown products promoted the growth of others unable to live in AGSP, forming an AGSP utilization network. The in vitro cell model showed that AGSP oligosaccharides had better anti-inflammatory activity and weaker cytotoxicity, implying that microbial degradation of AGSP can influence its reaction with host cells. These results indicated that the interaction between polysaccharides and gut microbes can together determine the beneficial effects of polysaccharides on the host health. (c) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study found that sulfated polysaccharides from pacific abalone can alter the gut microbiota structure and increase relative abundances of certain Bacteroidales members, indicating the important role of intestinal Bacteroidales in the bioactivities of AGSP. Additionally, there is an AGSP utilization network among Bacteroidales species, which influences the anti-inflammatory activity and cytotoxicity of AGSP.