Proton pump inhibitors bind proton pumps in the stomach. In layman terms, this prevents the stomach from producing acid. Less acid means that gastric juice that reaches the oesophagus is not as corrosive. This gastric juice can cause inflammation and irritation if your stomach acid is overly acidic. Medicine such as omeprazole can help reduce acidity of gastric juices by being a proton pump inhibitor.The symptoms of acid reflux include heartburn (chest pain) and a bitter or sour taste in the mouth and throat. Less commonly, it can also cause burping, bloating, hiccups and bad breath. These symptoms usually worsen if you are lying down or bending over, and tend to flare up after eating certain foods.