@rexsan20 I found this article published by the National Institutes of health, that talks about dry eyes and mouth, the autonomic nervous system, and Sjögren’s syndrome. A good portion is dense and scholarly, but there is enough to understand.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7685370/#:~:text=Dry%20eye%20and%20dry%20mouth,further%20dry%20eye%20work%2Dup.
Here is another article by this Dr. Driscoll that you mentioned and it’s easier to read.
https://vagusnervesupport.com/dry-eye-disease/

Is this similar to the podcast you talked about?