A gut-bacteria compound called imidazole propionate (ImP) has been linked to Alzheimer’s-related brain changes and faster cognitive decline, identifying a possible target for future treatments.
The study, published in Nature Communications, examined blood samples from 1,196 cognitively unimpaired adults and found that higher ImP levels were associated with poorer cognitive performance and biomarkers linked to Alzheimer’s disease. Researchers also identified gut bacteria capable of producing the metabolite and found that a genetic variation affecting ImP regulation was connected to both higher blood levels and Alzheimer’s risk. In experiments with mice, prolonged exposure to ImP worsened Alzheimer’s-like pathology, including the buildup of beta-amyloid and abnormal tau.
Additional laboratory tests indicated that ImP weakened the brain’s blood-vessel barrier and promoted tau phosphorylation in neurons, mechanisms that could help explain how a gut-derived chemical affects the brain. The human findings show an association rather than proof that ImP directly causes Alzheimer’s in people. Still, the results strengthen evidence that the gut–brain connection may influence neurodegenerative disease.
Scientists say future work could investigate drugs or other interventions designed to lower ImP levels, but no such treatment is currently available.