Volume 8 Number 1 2025
Alzheimer’s and the Gut Microbiota: Impacts on Brain Health, Memory, and Inflammation
Md. Al Noor Hossain1*, Salma jahan1, Anik Barman1, Sneha Sengupta2, Badhan Mojumder2
Microbial Bioactives 8(1) 1-8 https://doi.org/10.25163/microbbioacts.8110303
Submitted: 01 January 2025 Revised: 11 February 2025 Published: 12 February 2025
Abstract
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder marked by cognitive decline, memory loss, and neuronal degeneration. While genetic and environmental factors are well-established contributors, growing evidence highlights the gut microbiome as a potential modifiable risk factor in AD pathogenesis. The gut-brain axis, a complex communication network between the gastrointestinal tract and the central nervous system, plays a vital role in regulating inflammation, immune responses, and neurochemical signaling. Dysbiosis—an imbalance in gut microbial composition—has been associated with neuroinflammation, amyloid-beta accumulation, blood-brain barrier disruption, and cognitive dysfunction. Recent studies suggest that pathogenic bacteria such as Escherichia coli and Bacteroides fragilis may exacerbate amyloid-beta deposition and inflammation, while beneficial microbes like Lactobacillus and Bifidobacterium offer neuroprotective effects. Microbial metabolites, particularly short-chain fatty acids (SCFAs), are critical for maintaining neuronal health; diminished SCFA production correlates with increased inflammation and AD progression. Additionally, gut-derived lipopolysaccharides (LPS) can trigger systemic immune responses and chronic neuroinflammation via increased gut permeability (“leaky gut”). Probiotic and prebiotic interventions have shown promise in restoring microbial balance and improving cognitive outcomes, though clinical validation remains limited. Understanding the gut microbiome's influence on AD not only offers novel insights into disease mechanisms but also opens avenues for early diagnosis and microbiome-based therapeutic strategies. Continued research is essential to clarify causal relationships and develop effective interventions.
Keywords: Alzheimer’s disease, Gut microbiome, Neuroinflammation, Gut-brain axis, Microbial metabolites.
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