Microbiome signature of Parkinson's disease in healthy and genetically at-risk individualsOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study examined whether alterations in the gut microbiome track the development of Parkinson's disease (PD) in people who carry GBA1 gene variants but have not (yet) developed PD symptoms. The researchers combined clinical data with fecal metagenomics and used an analysis method that assessed both differential abundance of microbial species and the coherence of that abundance variation across groups, measured with Cliff's delta. The goal was to determine whether microbiome composition could serve as an early marker of PD risk in genetically at-risk individuals.
Who was studied?
The primary cohort included 271 patients with PD, 43 carriers of GBA1 variants who had not developed PD symptoms (GBA-NMC), and 150 healthy controls. Findings were then checked against three independent cohorts from the United States, Korea, and Turkey, together comprising 638 additional PD patients and 319 additional healthy controls. In total, the study drew on clinical and fecal metagenomic data from close to 1,400 individuals across four countries.
What were the most important findings?
About 25% of the gut microbiome in GBA-NMC individuals showed a composition that was intermediate between healthy controls and patients with PD. This intermediate microbiome signature was strongly correlated with disease progression in patients who already had PD, and with prodromal symptoms suggestive of future PD in both GBA-NMC and healthy individuals. Similar microbiome alterations were reproduced across the three independent international cohorts, strengthening confidence that the pattern is not specific to one population.
What are the greatest implications of this study?
The findings suggest gut microbiome changes can flag both genetically at-risk (GBA1 carriers) and non-genetically at-risk people in the general population who may be on a trajectory toward developing PD. This positions the microbiome as a potential early, non-invasive marker during the premanifest phase of disease, before clinical symptoms appear. Such a marker could eventually help identify candidates for early monitoring or intervention trials aimed at delaying or preventing PD onset.