Sulfated polysaccharides from Undaria pinnatifida improved high fat diet-induced metabolic syndrome, gut microbiota dysbiosis and inflammation in BALB/c mice.

Undaria pinnatifida was shown to reduce serum lipids and fat accumulation and produce beneficial effect on type 2 diabetes, but its effect on intestinal micro-ecology remains unclear. This study showed that sulfated polysaccharides from U. pinnatifida (UPSP) reduced weight gain, fat accumulation and metabolic disorders in mice fed with high fat diet (HFD). UPSP not only alleviated HFD-induced microbiota dysbiosis indicated as increased abundances of some Bacteroidales members that had positive correlations with the improvement of physiological indexes, but also maintained gut barrier integrity and reduced metabolic endotoxemia. A dose-effect relationship was observed between the dose of UPSP and its effect on some physiological indexes, gut microbiota community and nutrient utilization. The in vitro result showed that the use of Bacteroides species within Bacteroidales on UPSP was species-dependent, and the dose of UPSP affected the growth properties of some Bacteroides species. It implied that UPSP can be considered as prebiotic agent to prevent gut dysbiosis and obesity-related diseases in obese individuals.