Possible effects of antibiotics on the gut–brain axis and their possible influence on AD have been reviewed recently [125]: while amoxicillin, rifampicin, minocycline, rapamycin or doxycycline improved cognition, reduced Aβ deposition and accumulation of hyperphosphorylated tau, streptozotocin, ampicillin and cefepime were associated with memory deficits, reduced consciousness and confusion. Here, MAPT is linked to Alzheimer disease.