Effects of Probiotics, Prebiotics, and Postbiotics on Human Health

Recently, advances in microbiome research have emphasized the essential role of probiotics-in addition to their inanimate form, postbiotics, and psychobiotics, a rapidly expanding group of probiotics with psychotropic potential-in restoring disturbed microbial diversity in the human body. Much progress has been made through experimental studies in cell cultures or in animal models, enabling the investigation of underlying mechanisms in controlled biological settings, beyond the digestive tract and the maintenance of the intestinal barrier; this includes investigations of renal and respiratory physiology and function, bone and dental integrity, immune enhancement, and even modulation of psychiatric and neurobehavioral disorders. This expansion of focus beyond the gut reflects a transformative shift in our understanding of host-microbe interactions and opens promising paths for future therapeutic strategies. In this context, the current Special Issue brings together a collection of contributions illustrating both the depth and extent of current research in microbiome-directed interventions. Collectively, they reflect the remarkable conceptual and translational expansion of probiotic research. At the same time, the findings highlight the necessity of rigorous strain-level characterization, appropriate dosing strategies, and treatment duration, along with careful consideration of the metabolic, hormonal, and immunological status of the host; they confirm that probiotics are at the forefront of innovative, microbiome-targeted therapies, with their diverse biological actions and expanding therapeutic potential reflecting a rapidly evolving field with profound implications for personalized therapies as well as preventive medicine.