In addition, norovirus has also been isolated from patients with DLB, indicating active infection in the colon, secretion of a-synuclein by the intestine, and researchers found co-localization of norovirus and a-synuclein in different regions of the patient's brain, which is positively correlated with viral persistence, so maybe norovirus infection can migrate from the intestinal mucosa to the central nervous system through the autonomic nervous system and contribute to the development of disease [123,124]. Here, SNCA is linked to Lewy body dementia.