In the past decade, it has been realized that the diversity and balance of the gut microbiota plays a critical role for health. Gut microbiota and their metabolites interact with the host through a series of biochemical, immunological and physiological processes to affect the homeostasis and health of the host. Many studies have been reported that the disorders of the gut microbiota are associated with neurological diseases. Alzheimer’s disease (AD) is a complex neurodegenerative disease, its susceptibility and development are influenced by age, heredity and epigenetic factors. New evidence suggested that the composition change and translocation of the gut microbiota were associated with the development of AD, but its causal relationship and possible mechanisms need to be explored. Communications between the central nervous system and the gut axis relied mainly on three manners, including direct neural communication, endocrine pathways and immune regulation. Evidence from animal models of fecal microbiota transplantation and probiotic intervention suggested the association of gut microbiota with AD. Exogenous bacterial metabolites can directly impair neuronal function, and induce neuroinflammation to promote the onset of AD. In this review, we focused on the relationship and possible mechanisms of gut microbiota with AD, and provided evidence for possible interventions to prevent AD by improving the structure of gut microbiota.