With the acceleration of aging worldwide， the number of people living with cognitive impairment is rising， bringing a heavy burden on the patients， families， and society. However， the etiology has not been completely clarified. An increasing body of studies have shown that the gut microbiota is closely related to the occurrence of cognitive impairment. The gut microflora communicates with the central nervous system in a two-way manner through the gut-brain axis， and an imbalance in the gut ecosystem may lead to the occurrence and progression of cognitive impairment. The mechanisms may include neuroinflammation， barrier dysfunction， bacterial metabolite changes， and dietary changes. Cognitive function can be improved by adjusting the intestinal flora. The relationship between the gut microbiota and cognitive function can provide new insights into the prevention and treatment of cognitive impairment. ［Journal of International Neurology and Neurosurgery, 2023, 50(4): 90-94］