Coffee acidity has a sensory meaning: the brightness or tartness perceived in the cup. That description is not interchangeable with a laboratory pH result. A coffee marketed as low acid may therefore need further explanation before the label tells you much about either measurement or taste.
For flavor selection, compare the roaster's description, roast approach and processing information. Darker-roasted coffees often present less conspicuous brightness, but origin, processing and preparation still matter. A national origin alone cannot guarantee the result, because a country contains many growing conditions and producers.
If your goal is a less tart drink, buy a small quantity and compare it with your current coffee using the same recipe. Record whether you prefer the balance, rather than assuming the least bright cup is the best. Cold brewing creates a different extraction and serving routine, but it should not be presented as a universal solution to digestive symptoms. This guide concerns coffee selection and sensory descriptions; a product label does not establish an individual health outcome.
The conversation
A good question can make a better brew.