In recent years, the study of the human intestinal microbiota and its relationship with the brain has expanded enormously in the scientific field. It has been shown that changes in nutritional habits, apart from producing changes in the host microbiota, can affect the central nervous system, contributing to the development of neurological pathologies such as Parkinson's, Alzheimer's and motor neuron disorders. Several studies have shed light into the role of exercise as a preventive factor against various diseases; however, exercise can also produce stress on the body. This book discusses the relevance of an individual's health state, type and duration of exercise, and diet as contributing factors to the microbiota-gut-brain axis. Also, this book presents findings regarding the relationships between epigenetic modifications and the gut microbiota as well as between epigenetics and cognitive function.