Here, we found that the combination of DSW and fucoidan modulated the intestinal flora, especially the enrichment of Lactobacillaceae and Ruminococcaceae UCG 014, and decreased the levels of Bacteroides, which should be the synergistic effects of fucoidan and minerals in DSW, thereby changing the BA metabolism profile, affecting the host BA signaling and metabolic pathways, such as LA and arachidonic acid metabolism, enhancing insulin sensitivity, and preferably improving glycolipid metabolism in T2DM rats. The gene discussed is INS; the disease is type 2 diabetes mellitus.