Although antibiotics are used for fighting infections, long-term use of these medications can increase inflammation in the intestines. This can lead to a reduced production of stomach acid as your stress hormone levels increase. br Overusing nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and aspirin can also lead to lower production of stomach acid. These over-the-counter drugs can damage the stomach lining. br Also, a little stress once in a while does us no major harm, but when we develop chronic stress, it can destroy our digestive functioning and reduce our production of essential stomach acid.