Dementia and, in particular, Alzheimer’s disease (AD), affects millions of people around the
world and its prevalence is steadily rising annually. Some risk factors for AD, such as age, cannot be modified, while others could possibly be corrected. In recent years, many studies are
tackling the problem of the oral and gut microbiota as a provoking factor for AD and other
neurodegenerative diseases, but their relationship and specific pathophysiological mechanisms remain understudied. The microbiota of the oral cavity can be of particular importance
due to the specificity of microorganisms and their localization, as well as the possibility of
provoking neuroinflammation, which requires further study. This review covers the specific
features of the oral microbiota, current views on the pathophysiological role of the oral microbiota in the development of AD, as well as the beneficial role of probiotics. The study of this
issue can have an important practical application both for the early diagnosis of AD, and for
its further treatment.