Two new studies suggest certain proteins produced by gut bacteria could lead to neurodegenerative diseases.
Amyotrophic Lateral Sclerosis (ALS), Alzheimer’s and Parkinson’s diseases are all characterized by aggregates, or clumps, of amyloid proteins and misfolded alpha-synuclein, a naturally occurring brain protein. Physicians don’t know what initiates the aggregation in more than 90 percent of cases.
“These new studies in two different animals show that proteins made by bacteria harbored in the gut may be an initiating factor in the disease process of Alzheimer’s disease, Parkinson’s disease and ALS,” said Robert P. Friedland, MD, professor at the University of Louisville School of Medicine in a press release. “This is important because most cases of these diseases are not caused by genes, and the gut is our most important environmental exposure. In addition, we have many potential therapeutic options to influence the bacterial populations in the nose, mouth and gut.”
Researchers administered strains of E. coli bacteria that produce the bacterial amyloid protein curli to rats. A second group of rats was given E. coli bacteria that did not produce the protein. Compared to the control group, rats who received the amyloid-producing strain were found to have higher levels of the alpha-synuclein protein in the intestines and the brain as well as increased aggregates in the brain and brain inflammation. The research was supported by The Michael J. Fox Foundation.
A separate of roundworms fed curli-producing E. coli also showed increased levels of alpha-synuclein aggregates compared with the control group.