Gut microbiota in dementia with Lewy bodiesOriginal 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 gut microbiota composition and fecal bile acid profiles in patients with alpha-synucleinopathies, a group of neurodegenerative disorders. The researchers compared bacterial genera and short-chain fatty acid producers across dementia with Lewy bodies (DLB), Parkinson's disease (PD), and idiopathic REM sleep behavior disorder (iRBD). They used random forest models to identify microbial features that could distinguish DLB from PD, and they quantified fecal bile acids, including ursodeoxycholic acid (UDCA).
Who was studied?
The cohort included 278 patients with alpha-synucleinopathies, broken down into 28 patients with dementia with Lewy bodies, 224 patients with Parkinson's disease, and 26 patients with idiopathic REM sleep behavior disorder. This design allowed direct comparison of gut microbiota and bile acid patterns across three related but distinct neurodegenerative and prodromal conditions.
What were the most important findings?
Like PD, DLB showed decreased short-chain fatty acid-producing genera, but DLB uniquely showed increases in Ruminococcus torques and Collinsella, which were not seen in PD. Random forest models found that high Ruminococcus torques, high Collinsella, and low Bifidobacterium (a pattern also seen in Alzheimer's disease) were predictive of DLB status. Because Ruminococcus torques and Collinsella are major secondary bile acid producers, the researchers measured fecal bile acids and found elevated ursodeoxycholic acid (UDCA) production specifically in DLB.
What are the greatest implications of this study?
The findings suggest that DLB has a gut microbiota and bile acid signature distinct from PD, potentially reflecting increased intestinal permeability from Ruminococcus torques and Collinsella. The authors propose that increased UDCA in DLB may mitigate neuroinflammation at the substantia nigra, while neuroinflammation may be less critical at the neocortex, offering a possible explanation for regional differences in these diseases. Therapeutic strategies aimed at increasing Bifidobacterium and its metabolites may hold promise for slowing the development or progression of DLB.