Alzheimer's disease (AD) is a complex neurodegenerative disorder with potential links to oral health. Recent studies suggest that dysbiosis of the oral microbiome may influence the progression of cognitive decline in AD. This narrative review aims to systematically examine our current understanding of the relationship between oral health, the oral microbiome, and Alzheimer's disease. It focuses on identifying key mechanisms, and gaps in knowledge with the aim to direct future research and develop potential therapeutic interventions. The review includes a comprehensive search of peer-reviewed articles from 2014 to 2024, databases such as PubMed, Scopus, and Web of Science), focusing on clinical studies, systemic reviews, and meta-analyses. Preliminary findings indicated a consistent link between poor oral hygiene and elevated levels of specific pathogenic bacteria, such as Porphyromonas gingivalis, in the oral microbiome of Alzheimer's patients. These studies also suggest that individuals with greater oral dysbiosis exhibit more pronounced cognitive decline, as measured by various cognitive assessment tools. Furthermore, evidence from animal models supports the hypothesis that oral bacteria may contribute to neuroinflammation and AD pathology. These preliminary findings highlight the potential role of oral microbiome dysbiosis in the progression of Alzheimer's disease.