TL;DR
Get health and wellness essentials delivered free — and shop member deals
- Fast, free delivery on millions of items
- Access to Prime Big Deal Days deals on October 6–7
- Prime Video, Amazon Music and more included
Researchers report that imidazole propionate, a molecule produced by some gut bacteria, was linked to Alzheimer’s-related biological markers and faster cognitive decline in a study of nearly 1,200 people. Experiments in mice also found brain changes associated with the molecule, but the human findings do not show that ImP causes Alzheimer’s or that lowering it prevents the disease.
Researchers report that imidazole propionate (ImP), a molecule produced by some gut bacteria, may be connected to Alzheimer’s-related brain changes. In mice, ImP increased the accumulation of abnormal amyloid and tau proteins; among nearly 1,200 study participants, higher blood levels were associated with dementia-related biological markers and faster cognitive decline. The human findings show an association, not proof that ImP causes Alzheimer’s disease.
The team, led by researchers at the University of Wisconsin-Madison, examined ImP, a compound that certain gut bacteria produce while using the amino acid histidine for energy. ImP production varies among people. The researchers say bacteria capable of producing it are widespread, though generally not abundant. The molecule can enter the bloodstream after it is made in the gut, and earlier research had linked it to type 2 diabetes and coronary artery disease.
In mouse experiments, ImP that reached the brain was associated with increased accumulation of abnormal beta amyloid and tau, proteins tied to Alzheimer’s disease. The report says this process can lead to neuron death in people, but the mouse results do not establish that the same sequence occurs in humans exposed to ImP.
For the human analysis, researchers assessed blood samples from nearly 1,200 volunteers in the Wisconsin Registry for Alzheimer’s Prevention and studies through the Wisconsin Alzheimer’s Disease Research Center. People with higher ImP concentrations were more likely to show biological markers associated with abnormal proteins and impaired neuron function. The researchers also compared blood measurements with cognitive tests collected over time and reported faster decline among participants with the highest ImP levels. The source does not provide effect sizes or a clinical threshold for what counts as a high level.
A Potential Target Beyond Diet
The study points to a possible connection between gut bacteria, blood chemistry and brain changes, and suggests ImP may merit further study as a treatment target. If future research establishes that the molecule contributes to disease, treatments that lower its blood concentration could offer a more specific approach than trying to change the entire gut microbiome or remove a common nutrient from food.
That possibility remains several steps away from clinical use. The human findings are observational: higher ImP levels and faster cognitive decline occurred together, but the study as described does not show that one caused the other. Nor does it show that reducing ImP would prevent Alzheimer’s or slow decline. The mouse experiments provide evidence of a potential biological pathway, not evidence that an ImP-lowering treatment works in people.
The distinction matters for readers because a molecule linked to risk is not automatically a usable screening test or a treatment. The report gives no validated blood cutoff, prevention strategy or clinical guidance based on ImP. Its near-term importance is as a research lead that may help scientists investigate how metabolic products from gut microbes relate to dementia.
As an affiliate, we earn on qualifying purchases.
From Gut Microbes to Brain
The work builds on research begun nearly a decade ago by UW-Madison investigators Barbara Bendlin and Federico Rey. Their earlier studies found differences in the intestinal microorganism mix between people with Alzheimer’s disease and healthy individuals. The newer study asks how such differences might be linked to changes in the brain, focusing on a specific compound rather than gut bacteria in general.
ImP is produced as some bacteria generate energy from histidine, an amino acid needed by the body and present in many foods, particularly protein-rich foods. Bendlin cautioned that lowering ImP through diet alone may not be simple because histidine is widespread in foods and is essential to health. She said broad improvements in diet may help overall health, but the finding does not support avoiding particular foods to prevent Alzheimer’s.
The research involved collaborators from the University of California, Los Angeles and the University of Gothenburg. It was published in Nature Communications and received support from the Wisconsin Partnership Program, the National Institutes of Health and the U.S. Department of Agriculture, according to the report.
““But it’s not as easy as saying, ‘Stop eating eggs’ or ‘Don’t eat so much red meat.’ Because you need histidine, and it’s all over the place.””
— Barbara Bendlin, University of Wisconsin-Madison professor of medicine
brain health nootropic supplements
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Cause and Treatment Remain Open
The findings do not establish whether ImP contributes to cognitive decline in people, whether it rises as a consequence of other health or disease processes, or whether both reflect another factor. The report describes an association in participants and a biological effect in mice, but does not provide evidence from a clinical trial that lowering ImP changes Alzheimer’s risk or symptoms.
The researchers also identified a genetic variation associated with substantially higher ImP levels in the blood. About 43% of participants carried it. The team suspects the variation may affect how efficiently kidneys remove ImP, but the source presents that explanation as a hypothesis. It does not establish the kidney mechanism or clarify how much the variation contributes to an individual’s risk.
Further details are also needed to interpret the human results, including the size of the observed differences, the timing of blood measurements relative to cognitive changes, and whether the association holds across other populations. The report does not say that ImP testing is ready for clinical use.
As an affiliate, we earn on qualifying purchases.
Testing Ways to Lower ImP
The researchers’ proposed next direction is to investigate whether an inhibitor can reduce ImP in the blood and whether doing so affects brain-related outcomes. Such work would need to establish safety and show benefit in people before an ImP-targeting treatment could be considered for Alzheimer’s prevention or care.
Researchers can also examine the proposed relationship between the genetic variation, kidney clearance and blood ImP levels, and test whether the reported association with cognitive decline appears in other groups. Until those questions are answered, the study supports further investigation rather than a change in diet, a clinical test or a treatment recommendation.
cognitive support supplements for memory
As an affiliate, we earn on qualifying purchases.
As an affiliate, we earn on qualifying purchases.
Key Questions
What is imidazole propionate?
Imidazole propionate, or ImP, is a molecule produced by some gut bacteria as they use histidine for energy. It can enter the bloodstream and reach other parts of the body.
Does the study prove ImP causes Alzheimer’s disease?
No. The researchers found Alzheimer’s-related changes in mice exposed to ImP and an association between higher blood levels and markers and cognitive decline in people. Those results do not prove that ImP causes Alzheimer’s in humans.
Should people avoid foods that contain histidine?
The study does not recommend avoiding specific foods. Histidine is essential to health and is found in many foods. The researchers said lowering ImP through diet alone may be difficult.
Could lowering ImP prevent dementia?
That is a possibility the researchers want to investigate, not an established result. The study did not test an ImP-lowering drug or show that reducing the molecule prevents Alzheimer’s or slows cognitive decline.
Source: rss
Halloween Picks
halloween
As an affiliate, we earn on qualifying purchases.
