https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4869589/#!po=0....
I could go on...
The original commenter is encountering a lot of negative reaction because of his reliance on new age language to make his points in this community that hews strenuously to a concept of scientific methodology, but nonetheless he is correct that fever is mostly a protective adaptation that decreases infection mortality rates. Obviously there are temps above which fever can be damaging, so a complete abdication of intervention is not the way, but allowing fever for the most part to do its thing is helpful according to decades of mainstream medical research since the 80s.
Nowadays we know that most pH regulation is done with carbonate/bicarbonate via respiration, with ion transport managing electrolytes.
The alkaline diet has devolved to just throwing "bad" foods in the acidic bucket and "good" foods in basic, irrespective of chemistry:
https://waterforlifeusa.com/wp-content/uploads/2017/08/alkal...
He also has videos featuring "High Vibration" foods for "spiritual health".