Exploring the connections between Microbiome and Dementia: systematic review

Abstract

Introduction: disturbance in the balance of the intestinal microbiota, as an ecosystem, determines states of dysbiosis and dysregulation of the immune system, which are crucial for the onset of gastrointestinal and systemic diseases. Dementia is defined as an acquired syndrome, characterized by cognitive impairment and changes in mood or personality, which are severe enough to hinder social and occupational performance. Objectives: to describe the scientific evidence on the relationship between the gut microbiome and the onset/progression of dementia, and how it influences the underlying pathological mechanisms of different types of dementia. Methods: a search was conducted in Pubmed, Scopus, Web of Science from January 2000 to October 2022. Selecting abstracts of cohort and case-control studies evaluating the relationship between the gut microbiome and the onset/progression of dementia. Results: the results of this review suggest that there is a significant interaction between gut microbiota and mental health, supporting the idea that the gut and brain are bidirectionally connected through the gut-brain axis. However, it is important to note that many of these studies have limitations, such as small sample sizes and varied research designs, making it difficult to draw definitive conclusions. Therefore, more research is needed to fully understand the underlying mechanisms and clinical relevance of these relationships. Conclusions: this systematic review provides a comprehensive overview of the interaction between gut microbiota and mental health in diverse populations. The results suggest that gut microbiota may play an important role in mental health, but further studies are needed to confirm and better understand these relationships. These results have significant implications for research and the development of interventions targeting the gut microbiota as a potential approach to improve mental health in various conditions.