Yes, I came across that theory a little while ago, too.
NIH
"Dormant Viral Genes May Awaken to Cause ALS"
" . . . reactivation of ancient viral genes embedded in the human genome may cause the destruction in some forms of ALS. The result, suggests a link between human endogenous retro viral genes (HERVS) and ALS.
. . . raise the question of whether antiretroviral drugs, similar to those used for suppressing HIV, may also help some ALS patients."
The article goes on to say that humans have been passing on genetic remnants of ancient HERV infections, but the genes for these viruses were considered junk DNA, but motor neurons may be susceptible to activation of those genes in ALS.
I am just glad they are finally climbing out of their silos they've been in for 100 years, or is it that alternative theories that have been around for a long time are only now being given some credence and funding?
You cited a researcher studying bacteria as the cause for some neurodegenerative diseases: others are looking at common viruses. Regardless, I think we are still on the right track of thinking inflammation and the autoimmune system are still involved. The body starts attacking the pathogen but does not stop. I am still fascinated by the thought there could also be a fungal link, or who Knows, maybe a devastating combination of events that begins the fatal cascade.