For years, scientists have known that the gut microbiome of people with Alzheimer’s differs from that of healthy people. What remains unclear is whether these differences are a consequence of the disease, contribute to it, or simply accompany it. It is possible that part of the puzzle lies not in the gut bacteria themselves but in the molecules they produce, which end up circulating throughout the body.
\n\nA team of scientists believes it has found one such molecule. In a study published in Nature Communications, the researchers identified imidazole propionate (ImP)—a compound produced by certain gut bacteria—as a possible link between the microbiome and Alzheimer’s disease.
\n\nThe hypothesis put forward by the researchers begins in the gut. Some bacteria use an amino acid called histidine, and by metabolizing it, produce ImP. Some of this molecule can enter the bloodstream and circulate throughout the body.
\n\nThe problem begins at the brain’s border. Experiments in the new study indicate that ImP can weaken the blood-brain barrier, which protects the brain and controls what substances can pass into it via blood. A less effective barrier can help the metabolite enter the brain, where researchers found that it can interact directly with neurons.
\n\nThis…
Original source: https://www.wired.com/