Psychobiotics for nurturing the mental health through gut-brain-signalling: current status and future directions

The gut-microbiota-brain axis is a pivotal regulator of mental and neurological health, positioning psychobiotics as promising adjunct therapies. Specific microbial strains with inherent psychobiotic potential are known to enhance mental health, cognitive, or stress-preventive qualities. They mediate the promotion of a healthy intestinal barrier by the production of neurotransmitters, neuro-hormones and neuro-protectors, which include short-chain fatty acids (SCFAs), gamma-aminobutyric acid (GABA), serotonin, etc. This review explores the myriad ways that psychobiotics impact neurocognitive health and the potential use as an adjunct therapy for mental well-being. We further emphasise the revolutionary potential of nanotechnology in overcoming traditional delivery obstacles of psychobiotics with enhanced stability, bioavailability and efficacy, which are least explored in previous reviews. Hence, a detailed understanding of the development and applications of psychobiotics may offer new therapeutic possibilities and improved emotional balance. Together, these insights underscore the evolving landscape of psychobiotic research and outline future directions for developing more effective, microbiota-based interventions for mental health. The review affirms that, alongside the mechanistic effects of psychobiotics on neurocognitive health, the reinforcement of the gut-brain axis is pivotal. Thus, this review opens the scope for future investigations into personalised psychobiotics with site-directed enhanced action using nanotechnology.