Study from the University of Coimbra reveals how Parkinson's disease may have its origins in the gut

^{Translation by Diana Taborda}

A team of scientists from the University of Coimbra has revealed how Parkinson's disease can be triggered in the gut and then progress to the brain. The results of the study have just been published in Gut, the prestigious international journal in the field of gastroenterology, and add another important piece to the complex puzzle of Parkinson's disease, the second most common neurodegenerative disease in the world, which is expected to increase in the coming decades.

The study has been carried out over the last five years at the Centre for Neurosciences and Cell Biology of the UC (CNC-UC) and has been funded by the Santa Casa da Misericórdia de Lisboa (SCML) and the Portuguese Foundation for Science and Technology with a global amount of over half a million euros.

The team, led by Sandra Morais Cardoso, professor at the Faculty of Medicine of the University of Coimbra (FMUC), and Nuno Empadinhas, researcher at CNC-UC, studied the effects of chronic exposure of mice to BMAA, a toxin produced by cyanobacteria and other microbes that can accumulate in some aquatic animals such as mussels, shellfish and fish.

Building on previous studies suggesting the existence of different "types" of Parkinson's disease, the UC scientists have shown for the first time that chronic exposure to this environmental microbial toxin eliminates very specific groups of bacteria that protect the intestinal mucosa and regulate immunity within this essential barrier. Then a chain of events spreads to a specific region of the brain, primarily damaging the mitochondria, the organelles that act as the energy factories of cells.

Given that the clinical diagnosis of Parkinson's disease is only made when the first motor symptoms (tremors, muscle stiffness and slow movements) appear, this study shows that in some cases the disease may have been present in the gut for many years.

The full scientific article is available at: https://gut.bmj.com/content/early/2021/11/26/gutjnl-2021-326023