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.

海参中的岩藻多糖类是潜在的功能性食品成分，具有明确的重复结构。但是，岩藻依聚糖低聚糖的功能研究较少。在本研究中，我们首先在高脂饮食（HFD）喂养的小鼠模型中比较了来自Pearsonothuria graeffei（Dfuc- Pg）和Isostichopus Badionotus（Dfuc- Ib）的岩藻依聚糖低聚糖的功能作用。硫酸化模式是两种岩藻依聚糖寡糖中唯一的结构差异。Dfuc- Pg和Dfuc- Ib均抑制由HFD引起的高脂血症，肥胖症和炎症。值得注意的是，Dfuc- Pg可以抑制巨噬细胞浸润到脂肪组织中，并且具有比Dfuc- Ib更好的抗炎活性。同时，两种岩藻依聚糖寡糖都可以通过减少菌丝体的丰度而增加拟杆菌的丰度来逆转肠道菌群的营养不良，特别是结肠菌群的营养不良。然而，以2- O-磺基为主的Dfuc- Ib增加了变形杆菌的丰度。以4- O-磺基为主的Dfuc- Pg保持了更好的肠道菌群平衡。我们的结果为硫酸化寡糖的结构-功能关系提供了新的见解。