It is well known that the gut microbiota plays an extremely important role in modulating host physiological functions such as immunity and metabolic homeostasis. In recent years, accumulated evidence has revealed that the gut microbiota can regulate the functions of the central nervous system (CNS) through the gut–brain axis, which provides a novel insight into the interactions between the gut and brain. This review focuses on the molecular mechanism of the crosstalk between the gut microbiota and the brain via the gut–brain axis, and on the onset and development of neurological disorders triggered by gut microbiota dysbiosis. These topics are followed by a critical analysis of potential intervention strategies targeting gut microbiota dysbiosis, including the use of probiotics, prebiotics, synbiotics, and diets. While research on the microbiome–gut–brain axis is still in its relative infancy, clarifying the molecular mechanism that underlies how the gut microbiota regulates neurological functions not only holds the promise of revealing potentially novel pathogeneses of neurological disorders, but also may lead to the development of potential diagnosis biomarkers and intervention strategies targeting microbiota dysbiosis for neurological disorders.