Cranberry juice is a common treatment option for urinary tract infections (UTIs). However, in the case of a UTI due to E. coli, cranberry juice might not be the best form of treatment. E. coli bacteria prefer an acidic environment to thrive on, and cranberry juice is acidic. What you can do is pee on some pH paper to determine the acidity of your urine in the case of having a UTI. If your pH is neutral (7) or basic (>7), you can rest assure you will not add fuel to the fire by drinking cranberry juice (in this case it would be helpful).