Sargassum fusiforme Polysaccharides Prevent High-Fat Diet-Induced Early Fasting Hypoglycemia and Regulate the Gut Microbiota Composition

Abstract

A low fasting blood glucose level is a common symptom in diabetes patients and can be induced by high-fat diet (HFD) feeding at an early stage, which may play important roles in the development of diabetes, but has received little attention. In this study, five polysaccharides were prepared from Sargassumfusiforme and their effects on HFD-induced fasting hypoglycemia and gut microbiota dysbiosis were investigated. The results indicated that C57BL/6J male mice fed an HFD for 4 weeks developed severe hypoglycemia and four Sargassumfusiforme polysaccharides (SFPs), consisting of Sf-2, Sf-3, Sf-3-1, and Sf-A, significantly prevented early fasting hypoglycemia without inducing hyperglycemia. Sf-1 and Sf-A could also significantly prevent HFD-induced weight gain. Sf-2, Sf-3, Sf-3-1, and Sf-A mainly attenuated the HFD-induced decrease in Bacteroidetes, and all five SFPs had a considerable influence on the relative abundance of Oscillospira, Mucispirillum, and Clostridiales. Correlation analysis revealed that the fasting blood glucose level was associated with the relative abundance of Mucispinllum and Oscillospira. Receiver operating characteristic analysis indicated that Mucispinllum and Oscillospira exhibited good discriminatory power (AUC = 0.745–0.833) in the prediction of fasting hypoglycemia. Our findings highlight the novel application of SFPs (especially Sf-A) in glucose homeostasis and the potential roles of Mucispinllum and Oscillospira in the biological activity of SFPs.

Comparative Study of Sargassum fusiforme Polysaccharides in Regulating Cecal and Fecal Microbiota of High-Fat Diet-Fed Mice

“…Our recent study reported that five S. fusiforme polysaccharides prepared through hot-water and acid extraction showed a wide range of molecular weight (10-698.3 kDa), and the HCl-extracted polysaccharide (Sf-A) mainly consisted of glucose, fucose, and galactose [16]. Cheng et al prepared a 205.8 kDa S. fusiforme polysaccharide (SFF) by acid extraction and the polysaccharide was mainly composed of fucose and galactose [17].…”

“…Seaweed polysaccharides represent a kind of promising natural product that alleviates HFD-induced metabolic syndrome and promotes the healthy growth of gut bacteria [12]. In recent years, polysaccharides prepared from Sargassum fusiforme, a well-known edible alga, have attracted extensive research interest due to their potential biomedical application [13][14][15][16][17]. For example, our recent study indicated five polysaccharides prepared from S. fusiforme could selectively regulate the relative abundance of Oscillospira and Clostridiales in cecal microbiota of HFD-fed mice [16].…”

“…In recent years, polysaccharides prepared from Sargassum fusiforme, a well-known edible alga, have attracted extensive research interest due to their potential biomedical application [13][14][15][16][17]. For example, our recent study indicated five polysaccharides prepared from S. fusiforme could selectively regulate the relative abundance of Oscillospira and Clostridiales in cecal microbiota of HFD-fed mice [16]. Cheng and colleagues prepared an S. fusiforme polysaccharide that could decrease the relative abundances of the diabetes-related fecal microbiota [17].…”

“…For example, our recent study indicated five polysaccharides prepared from S . fusiforme could selectively regulate the relative abundance of Oscillospira and Clostridiales in cecal microbiota of HFD-fed mice [ 16 ]. Cheng and colleagues prepared an S. fusiforme polysaccharide that could decrease the relative abundances of the diabetes-related fecal microbiota [ 17 ].…”

“…In this study, two polysaccharides were prepared from S. fusiforme by water extraction (SfW) and acid extraction (SfA), and their chemical structures were characterized according to our recent report [ 16 ]. Then, the effects of 16 weeks of SfW and SfA administration on the cecal and fecal microbiota of HFD-fed mice were investigated.…”