Study Links Gut Metabolite ImP to Faster Alzheimer's Decline in 1,196 Adults

3 articles · Updated · WIRED · Aug 17

Blood tests from 1,196 cognitively healthy adults showed higher ImP levels tracked with worse cognitive scores, higher pTau-217 and NfL, and faster decline over time.
Nature Communications researchers traced a possible mechanism in which gut bacteria make ImP from histidine, the metabolite enters blood, weakens the blood-brain barrier, and then promotes amyloid-beta buildup and tau phosphorylation in the brain.
Months of ImP dosing in two Alzheimer’s-prone mouse models worsened disease signs, increasing amyloid plaques in some animals and tau abnormalities and astrocyte reactions in others.
ImP-producing bacteria are common and not sufficient on their own to cause Alzheimer’s; age, sex, genetics, diet, microbiome composition, and vascular or metabolic risks also shape how much of the metabolite reaches the bloodstream.
Rather than trying to eliminate the bacteria outright, the authors say a more practical future therapy may be to block ImP itself or the microbial machinery that produces it.