Bidirectional communications between the gut and the brain play an important role in the regulation of food intake, pain perception, mood, and cognitive function. The involved communication pathways are modulated by signals generated by the gut microbiome. Alterations in these communications have been implicated in several chronic brain and gut disorders, including food addiction, mood disorders, neurodevelopmental and neurodegenerative disorders, and functional and inflammatory bowel disorders. The gut microbiome holds great promise for the development of novel therapies normalizing altered brain-gut interactions.