Circulatory dietary and gut-derived metabolites predict early cognitive decline https://www.tandfonline.com/doi/full/10.1080/19490976.2026.2649487 6 neuroprotective metabolites are crucial https://www.pharmazeutische-zeitung.de/darmmikrobiom-kann-auf-abbau-hinweisen-165176/ They are neuroprotective molecules, namely choline, 5-hydroxyindoleacetic acid, and indolepropionic acid (IPA)