I have sibo and some gerd. I read John Hopkins looks into how much stomach acid one has. As we get older, we loose stomach acid. Nothing made me feel better except xifaxan 3times a day-550. I added Thorn betaine HCL Pepsin tablets-Amazon recommended by Chris Kessler. He has two at home stomach acids tests you can do your self. I had failed both. After only one day of this supplement I noticed huge difference.... And it was on a day I decided to cheat and ate several cookies. My gastro ignored me when I brought it up at first. Now I will have to educate him on this during my next appt!