The Role of Gut Bacteria in Affecting Brain Health and Its Relationship with Neurological Diseases

Background: The gut-brain axis represents a bidirectional communication network between the gastrointestinal system and the central nervous system, with gut microbiota playing a pivotal role in influencing brain health. Emerging evidence links gut dysbiosis to neurological disorders such as Parkinson’s disease, Alzheimer’s disease, and major depressive disorder. This study aimed to investigate the relationship between gut microbiota composition and neurological health by comparing individuals with neurological diseases to healthy controls. Methods: A quantitative, observational, case-control design was employed, involving 200 participants (100 with neurological disorders and 100 healthy controls). Fecal samples were collected, and microbial DNA was sequenced using the Illumina MiSeq platform targeting the V3-V4 regions of the 16S rRNA gene. Microbial diversity and composition were analyzed using bioinformatics tools (QIIME2, SILVA database). Sociodemographic, lifestyle, and clinical data were collected via questionnaires and medical records. Statistical analyses included t-tests, chi-square tests, and multivariable regression. Results: The neurological group showed significantly lower levels of beneficial bacteria (Bacteroides: 41% vs. 78%; Lactobacillus: 38% vs. 66%) and higher levels of potentially harmful genera (Clostridium: 71% vs. 40%; Escherichia: 64% vs. 33%) compared to controls. Neuropsychiatric symptoms were prevalent, with 35% exhibiting severe cognitive impairment and 44% severe mood disturbances. Lifestyle factors like sedentary behavior (62% vs. 36%) and high sugar intake (66% vs. 40%) were more common in the neurological group. Conclusion: The study confirms a distinct gut microbiota profile in individuals with neurological diseases, supporting the role of gut dysbiosis in neurological dysfunction. These findings highlight the potential for microbiota-targeted interventions (e.g., probiotics, dietary modifications) as therapeutic strategies. Further research is needed to establish causal mechanisms and develop personalized approaches for improving brain health through gut microbiota modulation.