This book reviews the pivotal role of prebiotics, probiotics, and postbiotics in modulating the gut–brain axis, offering insights into their potential therapeutic applications and impact on neurological health. The initial chapters provide a foundational overview of prebiotics and introduce readers to the concept of the gut–brain axis. These chapters discuss bidirectional communication within the gut–brain axis and the impacts of gut dysbiosis on neurological health. Further chapters investigate the relationship between the gut–brain axis and autoimmune diseases, as well as the role of probiotics in major neurodegenerative diseases such as Alzheimer’s and Parkinson’s, amyotrophic lateral sclerosis (ALS), Huntington’s disease, and conditions like multiple sclerosis (MS), epilepsy, and seizures. The book also examines the influence of prebiotics on mental health disorders such as anxiety and depression, and their impact on ischemic stroke via the gut–brain axis. It further covers the role of probiotics in reactive oxygen species (ROS) and inflammation-mediated neurodegenerative diseases and explores the correlation between gut microbiota, malnutrition, and neurological disorders. The book explores signaling pathways within the gut–brain axis and their relationships with neurological disorders, the application of prebiotics as functional foods, and the therapeutic potential of postbiotics and psychobiotics. This book is intended for scientists and researchers in the fields of microbiology, neuroscience, and gastroenterology. The book:Provides a thorough understanding of prebiotics, probiotics, and postbiotics, and their roles in the gut–brain axisExplores bidirectional communication within the gut–brain axis and its impact on neurological healthExamines the relationship between the gut microbiota and various neurological disordersDiscusses the influence of prebiotics and probiotics on mental health disorders such as anxiety and depressionInvestigates the connection between the gut–brain axis and autoimmune diseasesCovers advanced tools and bioinformatics approaches for studying gut microbiota and neurodegeneration