Experimental science, however, demands that one establishes a cause and effect relationship. There is no known cure of Alzheimer's disease, so one cannot refer to experimental medicine for an answer, with the exception of inherited dominant genetic mutations that impact only a small number of people. Unfortunately, of these mutations, those affecting the APP gene do not cause neuronal loss in mice; so the mouse models are inherently problematic.
This editorial calls for a clinical trial for antimicrobials in this disease. While I doubt that Alzheimer's is caused by infectious agents, there really is no harm in trying (except perhaps to the pockets of the trial's sponsors). In fact a trial of the antibiotic minocycline was completed in 2014 [1], however the results do not appear to have been reported.