A large body of research has shown the presence of a complex pathway of communications
between the gut and the brain. It is now recognized that, through this pathway, the microbiota
can influence brain homeostasis and plasticity under normal and pathological conditions.
This review aims at providing an overview of preclinical and clinical pieces of evidence supporting
the possible role of gut-brain axis modulation in physiological aging, in a neurodevelopmental disorder,
the autism spectrum disorders and in a substance abuse disorder, the alcohol addiction.
Since the normalization of gut flora can prevent changes in the behavior, we postulate that the gutbrain
axis might represent a possible target for pharmacological and dietary strategies aimed at improving
not only intestinal but also mental health. The present review also reports some regulatory
considerations regarding the use of probiotics, illustrating the most debated issues about the possibility
of considering probiotics not only as a food supplement but also as a “full” medicinal product.