Many of us like to sleep on our side. However, our sides are not created equal. Sleeping on the right side sabotages the functioning of the digestive system, especially for those who struggle with heartburn.Because our stomach is located on the left side of the body, sleeping on the left side makes connecting muscles easier between the stomach and the esophagus, or the food pipe, which helps control the acid reflux process. This is contrary to sleeping on the right, which relaxes them.