Alzheimer’s disease (AD) affects 5.5 million Americans and leads to progressive memory loss. Currently, there are few treatments to help prevent or slow this disease. Recently, the gut microbiota has emerged as a potential therapeutic target for AD, but little is known about which bacteria may be involved or how they contribute to AD. We think slowing the aging process in the microbiome could be used to help prevent or treat AD. We have found that colonizing mice with bacteria associated with AD can increase amyloid plaques. Our studies suggest this is because AD-associated bacteria block beneficial immune responses in the brain that help clear up amyloid beta plaques. Furthermore, we have found beneficial bacteria that can secrete substances that reverse this, and can increase the destruction of amyloid plaques. With additional studies, we are aiming to identify these bacterial substances that then could be used to activate the immune system in AD and prevent disease.