In this study, myofibrillar proteins (MP) from silver carp (Hypophthalmichthys molitrix) were modified by addition of 0, 2, 4 g/100 mL of Patinopecten yessoensis mantle polypeptides (PMP). By measuring the sulfhydryl contents, carbonyl contents, Fourier transform infrared (FTIR) spectra, ultraviolet (UV) absorption spectra and endogenous fluorescence spectra of MP and PMP-MP, we evaluated the effect of PMP on the structure of MP. The results showed that the total sulfhydryl, active sulfhydryl and carbonyl contents of MP decreased with increasing PMP concentration; there was no significant difference in the α-helix content of MP after modification, but the β-sheet content decreased and the β-turn content increased with increasing PMP concentration. The addition of PMP was beneficial to maintain the stability of MP structure. PMP also effectively delayed the carbonylation of MP. PMP can be considered as a potential natural antioxidant, cryoprotective agent and gel texture enhancer.

Globally, obesity has become the fifth leading risk factor for death, and discoverying prebiotics with preventive and therapeutic effects on obesity is a hot topic in current research. Marine polysaccharides, a special class of bioactive substances from marine organisms, have novel structural features and unique bioactivities due to the unique environment of the ocean. Marine polysaccharides have an excellent potential to treat obesity by regulating glucose and lipid metabolism, inflammatory factor levels, and the gut microbiota. This article reviews the types of marine polysaccharides, the effects of their structures and compositions on their antiobesity activity, and the underlying mechanisms of action. With the aim of providing a basis for the development of antiobesity drugs using marine polysaccharides, the article focuses on discussing the signaling pathways by which marine polysaccharides inhibit obesity through the gut microbiota, and gives an outlook on the application of marine polysaccharides for obesity inhibition.

Sea cucumber, an important marine food and medicinal resource, contains polysaccharides, which are one of the most important active substances in it. Sulfate groups play an important role in the biological activity of polysaccharides, and sea cucumber sulfated polysaccharides may specifically affect the growth of certain intestinal microorganisms and the production of related metabolites due to their different chemical structures, which contribute to the variable health promoting effects. As a complex ecosystem of the human body, the intestinal flora plays an irreplaceable role in life activities such as nutritional metabolism. Sea cucumber sulfated polysaccharides can be used as prebiotics to alleviate diseases caused by intestinal flora disorder by regulating its composition. This review article summarizes the structures of sea cucumber sulfated polysaccharides, with a focus on the latest progress in research on their influence on glycolipid metabolism through the gut microbiota. These studies will contribute to a better understanding of the health promoting mechanism of sea cucumber sulfated polysaccharides and provide a scientific basis for their application in functional foods.