I had to retrain my stomach to digest food using Betaine HCL. Here's an excellent article explaining it.

https://neurohacker.com/formulation/betaine

Now, DH is coming off years of PPI by using this system to rebuild his own acid management.

Here's a paper that says it works... as PART of PPI drug therapy.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7238915/

Which is, in a nutshell, our current pharmaceutical craze which substitutes for health.