The relationship between gut microbiota and neurodegenerative diseases: a genetic and epigenetic perspective.

Gut microbiota (GM) is a complex and dynamic structure that can have a wide range of effects on human health. Studies in recent years have shown that microbiota is not only related to the gastrointestinal tract (GIT) but also to the immune and endocrine systems. It causes various effects on host physiology, especially through genetic and epigenetic mechanisms. It shows that microbiota-derived metabolites can play a role in the development of neurological diseases by changing gene expression. In this review article, the relationship between GM and neurodegenerative diseases (NDs) is explained in terms of genetics and epigenetics. In terms of the gut–brain axis (GBA); the role of systems such as short-chain fatty acids (SCFA), vagus nerve, inflammatory responses and intestinal permeability in the pathogenesis of NDs such as Alzheimer's (AD), Parkinson's (PD), Huntington's (HD) and Multiple Sclerosis (MS) is discussed. In addition, experimental studies have drawn attention to the effects of changes in microbiota on neuroinflammation and cognitive impairment. In terms of treatment strategies; Probiotics, prebiotics, synbiotics, fecal microbiota transplantation (FMT) and nutritional interventions targeting microbiota seem to be promising strategies. However, the fact that microbiota structure varies between individuals indicates that studies in this area should be conducted in a more personalized manner. This article aims to provide a basis for future research by approaching the relationship between microbiota and NDs in a holistic manner.