The intestinal flora is recognized as a significant contributor to the immune system. In this research, the protective effects of oyster peptides on immune regulation and intestinal microbiota were investigated in mice treated with cyclophosphamide. The results showed that oyster peptides restored the indexes of thymus, spleen and liver, stimulated cytokines secretion and promoted the relative mRNA levels of Th1/Th2 cytokines (IL-2, IFN-γ, IL-4 and IL-10). The mRNA levels of Occludin, Claudin-1, ZO-1, and Mucin-2 were up-regulated, and the NF-κB signaling pathway was also activated after oyster peptides administration. Furthermore, oyster peptides treatment reduced the proportion of Firmicutes/Bacteroidetes, increased the relative abundance of Alistipes, Lactobacillus, Rikenell and the content of short-chain fatty acids, and reversed the composition of intestinal microflora similar to that of normal mice. In conclusion, oyster peptides effectively ameliorated cyclophosphamide-induced intestinal damage and modified gut microbiota structure in mice, and might be utilized as a beneficial ingredient in functional foods for immune regulation.

The benefits of omega‐3 (ω‐3) polyunsaturated fatty acids (PUFAs) to human health and the therapeutic properties of diseases have been widely identified. However, due to abundant double bonds, they are sensitive to environmental conditions which cause oxidative deterioration. This is one of the main factors limiting their application. The encapsulation of ω‐3 PUFAs is an effective way to improve their oxidation stability. This review summarizes the recent advances in different forms of ω‐3 encapsulation systems, such as emulsions, liposomes, microcapsules, and liquid crystalline. Particular emphasis is given to the effects of food‐derived biopolymers wall materials (proteins, polysaccharides, and esters) on encapsulation efficiency and oxidation stability of ω‐3 PUFAs encapsulation systems. In addition, the effects of natural antioxidants (polyphenols, carotenoids, flavonoids, plant essential oils, etc.) on the antioxidant enhancement of ω‐3 PUFAs encapsulation system based on food‐derived biopolymers are discussed. Different forms of ω‐3 PUFAs encapsulation systems have been proven to be used as supplements in the medical field. The regulation and improvement of the ω‐3 PUFAs encapsulation system on the diseases of animal and human, which are related to central nervous system, retina, lung, kidney and tissue cell, are systematically discussed.