TSLP and Alzheimer disease: YK4 (probiotic mixture consisting of Lactobacillus acidophilus CBT LA1, L. plantarum CBT LP3, Bifidobacterium breve CBT BR3, and B. lactis CBT BL3) inhibits the expression of skin thymic stromal lymphopoietin and serum immunoglobulin E induced by the excessive Th 2 cell-mediated responses of mice, thus mitigating AD [23].