Effect of the sulfation pattern of sea cucumber-derived fucoidan oligosaccharides on modulating metabolic syndromes and gut microbiota dysbiosis caused by HFD in mice

Fucoidans from sea cucumbers are potential functional food ingredients with a well-defined repeating structure. However, there have been fewer function studies of fucoidan oligosaccharides. In the present study, we first compare the functional effects of fucoidan oligosaccharides from Pearsonothuria graeffei (Dfuc-Pg) and Isostichopus Badionotus (Dfuc-Ib) in a high fat diet (HFD)-fed mouse model. Sulfation pattern was the only structural difference in the two fucoidan oligosaccharides. Both Dfuc-Pg and Dfuc-Ib inhibited hyperlipidemia, obesity, and inflammation caused by HFD. Notably, Dfuc-Pg could inhibit macrophages infiltrating into adipose tissue and had better anti-inflammatory activity than Dfuc-Ib. Meanwhile, both fucoidan oligosaccharides could reverse gut microbiota dysbiosis, particularly colonic microbiota dysbiosis by decreasing abundance of Firmicutes while increasing abundance of Bacteroidetes. However, Dfuc-Ib dominated with 2-O-sulfo groups increased abundance of Proteobacteria. Dfuc-Pg dominated with 4-O-sulfo groups maintained a better balanced gut microbiota profile. Our results shed a new insight into structure-function relationship of sulfated oligosaccharides.