How and why Parkinson’s disease (PD) starts and progresses is still not exactly known, but active research points to genetics and environment, among other factors. The environment is both external and internal – external in terms of what people encounter outside their bodies and internal in terms of what is inside their bodies. Researchers studying a variety of diseases have learned the importance of the microbiome in health and disease. The microbiome consists of all those bacteria, fungi, and viruses that occupy niches on and inside of people, such as on the skin, in the nose and mouth, and in the gut. These organisms can have far reaching effects in the body, distant from their own locations. Some of these interactions can affect the brain.

Ali Keshavarzian, MD, Chief of the Division of Digestive Diseases and Nutrition at Rush University in Chicago has been studying the role of the gut microbiome and its relation to inflammation, such as in inflammatory bowel disease, in addition to more distant sites including in the brain. His research includes the role of the gut microbiome as a contributing factor to the development and progression of PD as well as the potential to manipulate it to help manage the disease. He conducts both basic science research using animal models and clinical research with people with PD.