Type 2 diabetes mellitus (T2DM) is a complex metabolic disease threatening human health. We investigated the effects of Tegillarca granosa polysaccharide (TGP) and determined its potential mechanisms in a mouse model of T2DM established through a high-fat diet and streptozotocin. TGP (5.1×10³ Da) was composed of mannose, glucosamine, rhamnose, glucuronic acid, galactosamine, glucose, galactose, xylose, and fucose. It could significantly alleviate weight loss, reduce fasting blood glucose levels, reverse dyslipidemia, reduce liver damage from oxidative stress, and improve insulin sensitivity. RT-PCR and western blotting indicated that TGP could activate the phosphatidylinositol-3-kinase/protein kinase B signaling pathway to regulate disorders in glucolipid metabolism and improve insulin resistance. TGP increased the abundance of Allobaculum, Akkermansia, and Bifidobacterium, restored the microbiota abundance in the intestinal tracts of mice with T2DM, and promoted short-chain fatty acid production. This study provides new insights into the antidiabetic effects of TGP and highlights its potential as a natural hypoglycemic nutraceutical.

Inflammatory bowel disease, an intestinal relapsing inflammatory disease, not only impairs gastrointestinal function but also increases the chances of developing colon cancer. Currently, the effects of shrimp peptide (SP) in mice model of ulcerative colitis (UC) are still unclear. In particular, it is uncertain whether SP affects the gut flora with UC mice. In this study, we investigated the anti-inflammatory effects of SP on a dextran sulfate sodium (DSS)-induced mouse model of UC. Firstly, the molecular weight of SP was mainly distributed in the range of 180–1,000 Da (61.95% proportion), and the amino acid composition showed that SP contained 17 amino acids, of which, the essential amino acids accounted for 54.50%. In vivo, oral SP significantly attenuated the severity of colitis, such as diarrhea, weight loss, and rectal bleeding. Furthermore, treatment with SP remarkably ameliorated intestinal barrier integrity, thus lowering the levels of the inflammatory cytokines and ameliorating antioxidant indices and intestinal injury indicators in the serum and colon. Lastly, the cecal contents were used to sequence and analyze the 16S rRNA genes of bacteria. Results suggested that treatment with SP could restore the balance of intestinal flora in modeled mice by regulating the abundance of pathogenic and beneficial bacteria. Furthermore, SP could significantly improve intestinal flora dysfunction in mice with UC. In summary, our findings show that SP has a prophylactic and therapeutic effect in UC in vivo, thereby highlighting its broad medicinal applications.

Shellfish are diverse, widely distributed organisms that are a rich source of biological resources. Polysaccharides are an important components in shellfish, hence a great deal of attention has been directed at isolation and characterization of shellfish polysaccharides because of their numerous health benefits. Differences in shellfish species, habits, and environment result in the diversity of the structure and composition of polysaccharides. Thus, shellfish polysaccharides possess special biological activities. Studies have shown that shellfish polysaccharides exert biological activities, including antioxidant, antitumor, immune-regulation, hypolipidemic, antihypertensive, and antihyperglycemic effects, and are widely used in cosmetics, health products, and medicine. This review spotlights the extraction and purification methods of shellfish polysaccharides and analyses their structures, biological activities and conformational relationships; discusses the regulatory mechanism of shellfish polysaccharides on hyperlipidemia, hypertension, and hyperglycemia caused by lipid metabolism disorders; and summarizes its alleviation of lipid metabolism-related diseases. This review provides a reference for the in-depth development and utilization of shellfish polysaccharides as a functional food to regulate lipid metabolism-related diseases. To achieve high value utilization of marine shellfish resources while actively promoting the development of marine biological industry and health industry.

The oil derived from Psidium guajava seeds (TKSO) exhibits an abundance of diverse unsaturated fatty acids, notably oleic, linoleic, and α-linolenic acids, conferring substantial health advantages in addressing metabolic irregularities and human diseases. This research endeavor focused on elucidating the impacts of TKSO on colonic inflammatory responses and intestinal microbiota alterations in a murine model of colitis induced by dextran sulfate sodium (DSS), demonstrated that substantial supplementation with TKSO reduces the severity of colitis induced by DSS. Furthermore, TKSO effectively attenuated the abundance and expression of proinflammatory mediators while augmenting the expression of tight junction proteins in DSS-challenged mice. Beyond this, TKSO intervention modulated the intestinal microbial composition in DSS-induced colitis mice, specifically by enhancing the relative presence of Lactobacillus, Norank_f_Muribaculaceae, and Lachnospiraceae_NK4A136_group, while concurrently diminishing the abundance of Turicibacter. Additionally, an analysis of short-chain fatty acids (SCFAs) revealed noteworthy elevations in acetic, propionic, isobutyric, and butyric acids, and total SCFAs levels in TKSO-treated mice. In summary, these findings underscore the potential of TKSO to reduce the severity of colitis induced by DSS in mice through intricate modulation of the intestinal microbiota, metabolite profiles, and intestinal barrier repair, thereby presenting a promising avenue for the development of therapeutic strategies against intestinal inflammatory conditions.