This study shows that 3′-SL attenuates AD pathogenesis by inducing Tregs, thus inhibiting the production of the T cell subset (Th1, Th2, Th17) cytokines (e.g., IL-4, IL-5, IL-13, IL-17, IFN-γ, TNF-α, and Tslp) and reducing T cell activation. Here, IL4 is linked to Alzheimer disease.