Sodium oligomannate, which will shortly be studied as an investigational drug in a large AD phase III global clinical trial, suppresses gut dysbiosis together with the associated phenylalanine/isoleucine accumulation in an AD mouse model, resulting in reduced microglial activation, amyloid-β deposition, tau phosphorylation and amelioration of cognitive impairment39. This evidence concerns the gene MAPT and Alzheimer disease.