Bromelain aids digestion by enhancing the effects of the digestive enzymes trypsin and pepin. It can also help to prevent heartburn by ease diarrhea, if either are caused by a deficiency of digestive enzymes. Bromelain supplements often contain a plant pigment called quercetin. The two substances are found in combination simply because they enhance each other’s antiinflammatory actions, and that bromelain appears to improve quercetin absorption.