BDNF and Alzheimer disease: Also, using transplantation techniques, the microbiota of a rodent model of Alzheimer’s disease for C57BL/6 mice decreased neurogenesis in the adult hippocampus and Brain-Derived Neurotrophic Factor (BDNF) expression, and increased p21 expression, leading to memory impairment.68 However, the results of stratified CES in the present study showed no effect of MMD on offspring memory, suggesting that these changes observed in adult animals, at least for the present collection of data, may not be related to MMD.