 Men and women age 18-60 years who meet the Rome IV criteria for functional dyspepsia can participate in the study. For 14 weeks, patients need to discontinue their intake of proton pump inhibitors, drugs effecting gastric motility and NSAIDs. If a female participant takes oral anticonception, she has to switch to non-oral anticonception for this study. All participants will receive and sign a copy of the informed consent. 