Things shifted dramatically in 2017, with a seminal paper finding that germ-free mice inoculated with stool from Parkinson’s patients developed Parkinson’s symptoms. This study was widely heralded as a breakthrough in the field – the first time any neurodegenerative disease had been conclusively linked to dysregulations in the human microbiome.
Last year, Vo Van Giau, PhD, of Gachon University, South Korea, and his colleagues published an extensive review of the data suggesting a similar link with Alzheimer’s disease.
Dr. Giau and his coauthors laid out a potential pathogenic pathway for this interaction.
“The microbiota is closely related to neurological dysfunction and plays a significant role in neuroinflammation through the secretion of proinflammatory cytokines. Changes in the homeostatic state of the microbiota lead to increased intestinal permeability, which may promote the translocation of bacteria and endotoxins across the epithelial barrier, inducing an immunological response associated with the production of proinflammatory cytokines. The activation of both enteric neurons and glial cells may result in various neurological disorders,” including Alzheimer’s, he wrote.
Dr. Missling said this paper, and smaller studies appearing at Alzheimer’s meetings, prompted the company to add the stool sampling as a follow-up measure.
“It’s something of great interest, we think, and deserves to be investigated.”