I was googling for info on Poliquin’s “HCl test”, and one of the highly ranked results is the “rebuttal” article which bashes Poliquin’s nutrition & digestive physiology/anatomy knowledge. Nonetheless, there have been many anecdotal reports of successful relief of gastric distress following his advice. Curious, I did some searching on PubMed and found this interesting paper:
Apparently (with an admittedly very small initial test group), the researchers did, in fact, find that Betaine HCl supplementation increased stomach acidity substantially and rapidly. Fascinating.