The PD-GUT project is concerned with the origin of Parkinson's disease (PD), in particular whether PD begins in the gut. Traditionally, PD is considered a brain-only disease, but recent observations suggest that gastrointestinal (GI) tract involvement precedes motor symptoms. This project explores the hypothesis that gut inflammation is the initial trigger for PD. Understanding the early mechanisms of PD could lead to groundbreaking diagnostic, preventive, and therapeutic strategies. As PD affects millions of people worldwide, identifying its intestinal origins may transform disease management, improve patient outcomes, and reduce the societal and economic burden. The overall goal is to unravel the role of gut inflammation as the first insult in the development of PD, with the ultimate goal of identifying novel mediators involved in immune cell contributions to neurodegeneration. The project uses interdisciplinary approaches combining neuroscience, immunology and microbiology with advanced methodologies such as human induced pluripotent stem cells, three-dimensional model systems, organ-on-a-chip and single cell analysis. In addition to its potential to transform the understanding and treatment of PD, findings from the PD-GUT project could have significant implications for the study of other enteric diseases and microbial biology. Insights into the role of the gut in PD may influence treatment strategies for several conditions associated with gut inflammation and microbiome dysbiosis, highlighting the broader relevance of this groundbreaking research.