Alpha Synuclein: Gut Microbiota

Interactions between the digestive and central nervous system has provided evidence connecting changes in the gut microbiota to neurological diseases. Individuals suffering from PD experience loss of smell, insomnia, and constipation years before the PD associated movement issues occur. But, clinicians and researchers almost never link the pathological changes in the gut that occur early on with the later disease prognosis. A group of Danish scientists showed that a full truncal vagotomy was linked to a lowered risk of PD, compared to control patients. A vagotomy is a surgical procedure that involves cutting at least one branch of the vagus nerve that links the digestive system and nervous system. In another study, an alpha synuclein overexpressing mouse model established that mice brought up in a germ-free environment with a depleted gut microbiota exhibited less development of PD pathophysiology (motor dysfunction, neuroinflammation, and alpha synuclein pathology). Finally, an American study showed that PD patients displayed a smaller number of bacteria with anti-inflammatory properties and a larger number of proteobacteria. The connection between the gut microbiota and the nervous system could lead to a new method of PD treatment outside the normal domain of therapy²⁷.