Bio-Active Peptides from Marine Sources: Mechanistic Insights into Immune Regulation, Microbiota Modulation, and...

Natural bioactive chemicals sourced from marine species have attracted growing interest due to their immunomodulatory, antioxidant, and gut microbiota-regulating characteristics. These chemicals, especially peptides, offer therapeutic approaches for addressing inflammation, immunological dysfunction, and intestinal barrier disturbance, which are frequently observed in conditions such as inflammatory bowel disease (IBD). This review centers on current discoveries about marine-derived peptides from octopus, sea conch, and scallop. These substances have demonstrated a considerable ability to restore intestinal integrity, regulate immune cell function, reduce pro-inflammatory cytokines, and rebalance dysbiotic gut microbiota. We consider several in vivo scenarios, encompassing dextran sulphate sodium (DDS)-induced colitis and cyclophosphamide-induced immunosuppression. These compounds raise the expression of tight junction proteins (including ZO-1 and occludin), boost the production of mucin, and encourage the growth of good bacteria such as Lactobacillus and Lachnospiraceae. Their effects are mechanistically associated with the inhibition of critical inflammatory pathways (e.g., Nuclear factor-κB (NF-κB), Toll-like receptor 4 (TLR-4)) and the modulation of both innate and adaptive immune responses. These versatile bioactives can serve as dietary supplements or complementary therapies for gastrointestinal and cancer-related issues. This review emphasizes the therapeutic potential of marine peptides, concentrating on gut-immune-microbiota interactions, as well as exploring future avenues for clinical translation and drug development.