A molecule made by gut bacteria has been linked to faster cognitive decline and markers of Alzheimer's disease in a study led by researchers at the University of Wisconsin–Madison. The finding has been circulating widely, most recently in a ScienceDaily report this month.
For families worried about dementia, the study is interesting science, not a new prevention plan. The researchers found an association in people. They did not show that lowering the molecule protects memory, and no diet or probiotic has been proven to lower it.
