If it's a true sourdough (fermented for at least 7 hours) it would not contain any yeast. Obviously this is not a true sourdough with yeast as an ingredient. I'm sure there's quite a bit less gluten in the product than there would be in regular yeasted bread, because that's one of Rudi's specialties.
If you're prone to candida I would steer clear. Look for an organic loaf which would normally contain organic wheat flour, starter culture (enzymes), water and salt basically. Better yet, buy a starter culture and try a loaf at home
Whoops just noticed that wheat gluten and wheat starch are also ingredients, so this is in no way a low gluten bread....BUT since you haven't reacted it may be safe for you. Next time look for an organic fermented loaf.