Modulation of hyperglycemia by sodium alginate is associated with changes of serum metabolite and gut microbiota in mice

Previous studies showed that sodium alginates of different molecular weights reduced postprandial glucose differently. We hypothesize that the differential modulation of hyperglycemia by sodium alginates with different molecular weights may be associated with their differential regulations of serum metabolites and gut microbiota. In this work, high-fat diet-fed mice were supplemented with high- and low-molecular-weight sodium alginate (H-SA, 3350 kDa; L-SA, 131 kDa). Blood glucose/lipid parameters, serum metabolites and gut microbiota were measured. Compared with L-SA, H-SA more significantly reduced fasting blood glucose, HOMA-IR, total cholesterol and body fat; H-SA more significantly enriched serum metabolites, including certain lipids, branched-chain amino acids, and vitamin D and E derivatives. These changes were correlated with the differential modulation of gut microbiota by H-SA and L-SA. In conclusion, the differential effects of sodium alginates with different molecular weights in alleviating hyperglycemia were associated with their differential modulations of serum metabolites and gut microbiota.