Probiotic Trigger Molecules in Action

Probiotics are becoming increasingly popular and widely consumed worldwide. However, the term “probiotics” is extremely broad considering it encompasses a variety of microorganisms with a range of beneficial effects. The use of probiotics spans across centuries, from their historical functionality in food fermentation to the recently recognized potential for attenuation of different disorders through their effects on the human microbiome. Study of the latter has been influenced by the growing appreciation of the importance of gut microbiota to host health and the recognition that many disorders may arise from disruption of that microbiota. In addition to the therapeutic applications of probiotics in the treatment of metabolic disorders, which are characterized by dysbiosis of intestinal microbiota located in the gastrointestinal tract, new therapies are being explored, including treatment of disorders that are seemingly unrelated to the gastrointestinal region (e.g., neurodegenerative disease). Though probiotic strains have been extensively investigated, the mechanistic basis of their health-promoting effects remains unclear. Therefore, the aim of this Research Topic is to gather the recent research related to the characterization of potential probiotic trigger molecules. In particular, we welcome studies on structural and/or functional characterization of surface-exposed cell components (such as S-layer proteins, pili, lipoteichoic acid, etc.) or those released in the microenvironment (such as exopolysaccharides) ; these particular cellular compounds are the first to interact with the strain-producer microenvironment. In addition, research related to certain intracellular enzymes (e.g., proteases, bile salt hydrolases, etc.), specific biomolecules (such as bacteriocins), or widely synthesized products with the potential to act as probiotic trigger molecules will also be welcomed.