Most people need MORE acid...look into stomach acid test ... probably should be taking HCL W/Betaine
I read somewhere that low stomach acid can cause acid reflux. There’s a sphincter at the base of the esophagus that closes in response to the presence of stomach acid. But if the acid is weak, it gets only a weak signal to close and you wind up with acid getting by and causing burning. The solution was to drink a tablespoon of vinegar as counterintuitive as that sounds. I can’t remember where I read it, and I’ve never tried it, but I thought it was an interesting angle.