Postbiotic metabolites produced by lactic acid bacteria: a molecular and functional overview

Abstract

Lactic acid bacteria (LAB) are microorganisms of great industrial relevance and represent a business of billions of dollars worldwide because of their food, biotechnological and therapeutic applications. LAB have a long and safe tradition in the production of various fermented foods since they are widely used as starter cultures. They play a key role in food technology not only for their ability to produce lactic acid and for their contribution to the organoleptic properties of the final product, but also for their beneficial effects on the consumer health. Recently, certain LAB strains have been increasingly marketed as postbiotic bacteria referring to preparations of non-viable microorganisms and / or their metabolites and cellular components that, when administered in adequate amounts, exert a beneficial effect on health. Among postbiotic metabolites produced byBAL, some of the better known include B-vitamins, short chain fatty acids (acetate, propionate and butyrate), antimicrobial peptides such as bacteriocins and neurotransmitters such as γ-aminobutyric acid (GABA). Thus, postbiotic metabolites have many health-regulating functions in the body, including absorption of nutrients, detoxification, regulation of the immunesystem and gut-brain communication. The brain?gut?microbiome axis is a bidirectional communication pathway between the gut microbiota and the central nervous system. The growing interest in the gut microbiota and mechanisms of its interaction with the brain has contributed to the considerable attention given to the potential use of probiotics, prebiotics and postbioticsin the prevention of mental disorders. Here, I will present our recent advances about the molecular and functional analysis of metabolites produced by autochthonous LAB strains (CERELA Culture Collection) and postulate the potential impact on the gut microbiota ecology.