Gut Microbiota Dysbiosis Induced by Decreasing Endogenous Melatonin Mediates the Pathogenesis of Alzheimer's Disease and ObesityOriginal 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?
Researchers examined whether reduced endogenous melatonin drives Alzheimer’s disease and obesity through gut microbiota changes. They used mice genetically deficient in Aanat, the rate-limiting enzyme for melatonin synthesis.
How was it studied?
The endogenous melatonin reduction (EMR) mouse model underwent multi-omics profiling of transcriptomes across 11 organs, serum metabolomics, and gut microbiota analysis. Fecal microbiota transplantation (FMT) was then used to test whether restoring microbiota could reverse the observed effects.
What did they find?
EMR mice showed pan-metabolic disruption, microbiota dysbiosis, increased gut permeability, and systemic inflammation, the latter correlated with higher Ruminiclostridium_5 abundance. By 8 months, EMR mice displayed Alzheimer’s-like features (Iba-1 activation, amyloid-beta deposition, impaired spatial memory) plus greater weight gain and hepatic steatosis on a high-fat diet. FMT improved gut permeability, systemic inflammation, and both the Alzheimer’s-like phenotype and obesity.
Why it matters
The findings position gut microbiota dysbiosis as a mechanistic link between low melatonin and two distinct disease processes, Alzheimer’s disease and obesity. This suggests the gut microbiome could be a shared target for preventing or treating both conditions.