This article mentions studies connecting gum disease, pancreatic cancer, Alzheimer’s and heart disease.
Bacteria causing cancer seems unusual to me, but I have little knowledge of medicine and biology.
That’s not exactly a quality publication there.
I have seen other research pointing to bacterial involvement in heart disease; mainly in plaque formation.
Looking for connections between microbiology and all sorts of diseases is an interesting area of ongoing research right now. A few tidbits have been found here and there that hint at possible connections, but the actual evidence is quite thin - enough to prompt further investigation, but FAR from enough to draw any conclusions yet.
This “article” - really a barely-veiled ad for dental services - is simply cherry picking a handful of published data points, making an Evel Kineval-sized leap of logic, padding the empty conclusions with a bunch of weasel words, and promising impossible benefits that are wholly unjustified.
I haven’t read the article but wonder if it’s referring to Helicobacter pylori, the bacteria that came to fame when its role in the cause of ulcer disease became known.
For example, here’s a paper that suggests a possible, but by no means conclusive, link between H. pylori and pancreatic cancer.
And, here’s a review on the possible link between H pylori and atherosclerosis.
There is much less worth citing, though, regarding H pylori and dementia, just a few speculative reports (IMO). Here is one such paper.
Thanks, Smeghead.
I can worry about my teeth, not pancreatic cancer. 
The link between gum disease and heart disease is extremely strong, that one’s not even in question, and has been understood since the early 90s at least. Heart disease runs deep in both my parents’ families, and I take scrupulous care of my teeth and gums as a result.
Perhaps heart disease causes gum disease.
No, the microbe that causes gum disease gets into the bloodstream and starts damaging the artery walls, IIRC.