Correlation between Alzheimer's Disease and Gastrointestinal Tract Disorders

Area of Science:

• Neuroscience
• Gastroenterology
• Microbiology

Background:

• Alzheimer's disease (AD) is a leading cause of global dementia, characterized by amyloid-β plaques, neurofibrillary tangles, and synaptic loss.
• The multifactorial pathogenesis of AD is not fully understood, with emerging evidence linking the central nervous system to the gastrointestinal tract.
• The gut microbiome and gastrointestinal disorders are increasingly implicated in AD onset and progression.

Purpose of the Study:

• To explore the association between gastrointestinal health, the gut microbiome, and Alzheimer's disease.
• To investigate the mechanisms by which gut dysbiosis and inflammation may contribute to AD pathogenesis.
• To identify potential therapeutic strategies targeting the gut microbiome for AD management.

Main Methods:

• Review of studies examining the link between AD and gastrointestinal diseases (periodontitis, H. pylori infection, IBS).
• Analysis of the role of the gut microbiome and the microbiota-gut-brain axis in central nervous system function.
• Exploration of the impact of gut inflammation and permeability on AD pathology.

Main Results:

• Positive associations found between AD and conditions like periodontitis, H. pylori infection, and inflammatory bowel disease.
• Gut microbiome alterations (quantity and diversity) are observed in AD patients, even preclinically.
• Mechanisms include H. pylori entry into the CNS, systemic inflammation from periodontitis, and increased intestinal permeability contributing to neuroinflammation.

Conclusions:

• The gut microbiome and gastrointestinal tract play a significant role in Alzheimer's disease pathogenesis.
• Inflammation and microbial metabolites traversing the microbiota-gut-brain axis are key contributors to AD progression.
• Therapeutic interventions targeting the gut microbiome, such as antibiotics, probiotics, prebiotics, and fecal transplantation, show promise for AD treatment.