Microbiota and Neurodegenerative and Brain Diseases

The microbiota is the immense set of all types of microorganisms (bacteria, viruses, fungi, protozoa, etc.) that inhabit the human body, presenting marked differences between all parts of the body depending on the physical-chemical characteristics of a given area. This chapter focuses on the study of the influence of the microbiota on the appearance of neurodegenerative and brain diseases. Various types of diseases caused by degeneration of the brain parenchyma will be treated, such as Alzheimer’s and Parkinson’s diseases, and by alterations or disorders in the functioning of the brain or psychiatric diseases.