Bugs and Brains: The Microbiome & Dementia

Abstract

Interest in the microbiome and its correlation with different neurological diseases has grown significantly over the past decade. The gut microbiome contains a vast array of diverse organisms living in the gastrointestinal (GI) tract. Predominantly composed of bacteria, the gut microbiome helps regulate homeostasis and metabolism in the host, aiding in immune system development as well as vitamin and nutrient absorption. Studies suggest that, in addition to providing humans with these physiological benefits, the gut microbiome is also linked to and communicates with the brain via the gut-brain axis (GBA). Long-standing research on the GBA has demonstrated that the GI tract and the central nervous system are interconnected through both neurological and immunological signaling pathways. Recent research is expanding our understanding of the microbiome and the GBA, revealing correlations between the microbiome impact on the GBA and neurological conditions such as Alzheimer’s dementia and Lewy body dementia, going as far as to identify and highlight specific microbial species that may serve as risk or protective factors for various forms of dementia. This letter aims to highlight the current findings and recommend the use of tools such as microbial cell-free DNA testing to gain a better understanding of the role of gut dysbiosis in dementia patients.