There is a fair amount of more recent research in support of a microbial contribution to Alzheimers, and rather than just mediating through inflammation, disrup

There is a fair amount of more recent research in support of a microbial contribution to Alzheimers, and rather than just mediating through inflammation, disrupting metabolism in ways that accelerate amyloid deposition. I believe this ties more closely with research into vascular amyloid, if you look at who is involved, which may be why you haven't encountered it. You might see https://doi.org/10.3389/fnagi.2017.00336 https://doi.org/10.3389/fnagi.2017.00336 as a sample review paper that talks about oral bacteria that are capable of spurring amyloid formation in addition to spirochetes. Lastly one of the complaints I've heard from someone involved in the cerebrospinal fluid drainage side of Alzheimer's research is that it is really, really hard to fight the amyloid clearance by immunotherapy dominant faction to get any funding or attention for alternatives. They just don't want to hear it.