ANALYZING THE GUT-BRAIN AXIS IN ALZHEIMER'S DISEASE: A MICROBIOME-CENTRIC APPROACH

Abstract

The gut-brain axis has emerged as a crucial biological network influencing the onset and progression of Alzheimer’s disease (AD). This study explored the relationship between gut microbiota dysbiosis and AD-related neurodegeneration by synthesizing evidence from recent literature. The findings revealed that individuals with AD demonstrated significantly lower microbial diversity, higher systemic inflammation (IL-6, TNF-α, CRP), and disrupted metabolite levels (e.g., SCFAs, tryptophan) compared to healthy controls. Additionally, neurotransmitters critical for mood and cognition, including serotonin, dopamine, and GABA, were markedly diminished in the AD group. These alterations correlated strongly with cognitive deficits, as measured by standardized tests such as MMSE, MoCA, and ADAS-Cog. Interventional strategies targeting the microbiome—such as probiotics, prebiotics, and dietary modifications (notably the Mediterranean diet)—were associated with improved gut composition and better cognitive performance. Probiotic treatments like Lactobacillus and Bifidobacterium improved both gut diversity and MMSE scores. Dietary interventions reduced CRP levels and enhanced cognitive outcomes. Figures and tables presented in the study support the hypothesis that gut-brain axis modulation may serve as a viable adjunctive or preventive strategy in AD treatment. This research highlights the need for a paradigm shift from a purely neurocentric model to one that integrates microbial ecosystems as key regulators of brain health.