Fermented Fish Products: A Comprehensive Overview of Traditional Processing Techniques, Varieties, and Their Health Benefits.

This review addresses the processing aspects and integrates in vitro and in vivo findings to highlight the various health benefits of indigenous fermented fish products from different regions of the world. Across Asia, Africa, and Northern Europe, fermented fish holds cultural significance, with each region boasting unique varieties shaped by local traditions. This literature examined published articles on the various therapeutic properties of fermented fish by focusing on its lactic acid bacteria (LAB), antioxidant, anticancer, gut microbiota, and antimutagenic activities. Fermentation of fish products using starter cultures of Lactobacillus, Enterococcus, and Monascus purpureus enhanced the production of peptides and improved digestibility. Fermented fish substrates inoculated with Lactobacillus and Bacillus spp. generated bioactive peptides (e.g., FSGLR, IAEVFLITDPK, NVPVYEGY) with antioxidant and antihypertensive potential, thereby enhancing the nutritional and functional quality of traditional fermented fish products. These peptides modulated gut microbiota (↑Bacteroidetes, ↓Firmicutes) and metabolites, while fermented fish collagen suppressed oxidative stress (↓NOX, ↓MITF, ↓TYR) and activated GlyR/GlyT and SOD pathways. Fermented fish products are valuable sources of antioxidant and anticancer peptides. However, further research is needed to improve food safety by enhancing hygiene practices and controlling microbial contaminants.