The acidity from 5 Candida Force isn't enough to cause ulcers. There are many breakdowns in tissue function that have to take place for ulcers to happen - imbalances in bacterial flora, loss of absorption of nutrients, decreased levels of mucus production, etc.

H. pylori has been linked to ulcers, but all of the above has to happen first. People who don't have H. pylori have been found to have more allergies and incidence of asthma.