This review focuses on Alzheimer's disease, which is characterized by cognitive impairment that affects daily life and is linked to the formation of amyloid beta plaques and neurofibrillary tau fibrils. Recent findings point to a link between gut microbiota and Alzheimer's disease, with individuals with Alzheimer's disease and mild cognitive impairment (MCI) having a lower diversity of microbiota. Studies point to similarities in the gut microbiota of MCI and Alzheimer patients, which provides insights into the pathogenesis before dementia. The review also addresses lifestyle and dietary patterns such as the Mediterranean diet, DASH, MIND, and the ketogenic diet as potential non-pharmacotherapeutic approaches to modulate neuropathological AD markers. The aim is to better understand the function of the intestinal microbiota, the effects of diet and its links to Alzheimer's disease, taking into account factors such as genetics, age, antibiotics and diet.