Growing evidence suggests that the gut microbiome plays a crucial role in Alzheimer's disease (AD) pathogenesis through the microbiota-gut-brain axis, with alterations in gut microbiome composition linked to increased intestinal permeability, blood-brain barrier impairment, and neuroinflammation, and that gut microbiome modulation may alleviate AD symptoms, serve as a preventive measure, and also address comorbidities like Type 2 Diabetes Mellitus (T2DM), with future research directions including fecal microbiota transplantation (FMT) and precision medicine.