Scientists discover links between Alzheimer's disease and gut microbiota
I had to triple check the date because I was pretty sure that this was known before.   Maybe it is simply the confirmation aspect of it?Edit:> Our findings reveal for the first time, that Alzheimer’s symptoms can be transferred to a healthy young organism via the gut microbiota, *confirming a causal role* of gut microbiota in Alzheimer’s disease ...From: https://faculty.sites.uci.edu/kimgreen/bio/glucocorticoids-a...Citing many papers> One early event in AD is an increase in circulating glucocorticoidsYou could sum up Alzheimer's as: 
Diet/Lifestyle + a congenital form of Cushing's syndrome and you have increasing glucocorticoids which imply downregulation of the PVN, less progesterone and low levels of Prolactin reducing oligodendrocyte reducing myelin sheaths.  Add in APOE e4 without choline in the diet and you have accumulation of lipids to round it all out.There is a reason why Omega 3 + B+D vitamins are talked about as preventative as they all reduce inflamation.See this for example: https://www.grassrootshealth.net/two-nutrients-proven-stop-b...Edit2: For the curious here is a larger brain dump on the topic with many more links when I had to untangle the pathway earlier this year while working on something else.
  https://www.reddit.com/r/DrWillPowers/comments/16ae4zy/alzhe...