Postbiotics of Marine Origin and Their Therapeutic Application

The increase in antibiotic-resistant pathogens has prompted the search for alternative therapies. One such alternative is the use of probiotic microorganisms. However, growing interest is now turning toward postbiotics—non-viable microbial cells and/or their components or metabolites—that can confer health benefits without the risks associated with administering live microbes. Marine ecosystems, characterized by extreme and diverse environmental conditions, are a promising yet underexplored source of microorganisms capable of producing unique postbiotic compounds. These include bioactive peptides, polysaccharides, lipoteichoic acids, and short-chain fatty acids produced by marine bacteria. Such compounds often exhibit enhanced stability and potent biological activity, offering therapeutic potential across a wide range of applications. This review explores the current knowledge on postbiotics of marine origin, highlighting their antimicrobial, anti-inflammatory, immunomodulatory, and anticancer properties. We also examine recent in vitro and in vivo studies that demonstrate their efficacy in human and animal health. Some marine bacteria that have been studied for use as postbiotics belong to the genera Bacillus, Halobacillus, Halomonas, Mameliella, Shewanella, Streptomyces, Pseudoalteromonas, Ruegeria, Vibrio, and Weissella. In conclusion, although the use of the marine environment as a source of postbiotics is currently limited compared to other environments, studies conducted to date demonstrate its potential.