Sign up to our free Living Well email for advice on living a happier, healthier and longer life Live your life healthier and happier with our free weekly Living Well newsletter Live your life healthier and happier with our free weekly Living Well newsletter A sourdough bagel might not be your first choice this National Bagel Day – but it could be a better option for people looking to improve their gut health. That’s because of the way sourdough bread is made, using just a handful of simple ingredients. It has no yeast or chemical additives, like other kinds of bread. “When buying sourdough, look at the ingredient list,” Hartford HealthCare’s Dr. Ulysses Wu advised. “The best versions have just flour, water, and salt, and ideally use whole grain flour for added fiber.” open image in gallery A sourdough bagel could be a healthier choice this National Bagel Day (Getty Images for ESPN) The secret’s in the starter Unlike regular bread, sourdough is made using a starter: a live culture of wild yeast and bacteria. …