The goal of this study is to evaluate the feasibility of a decentralized clinical trial in South Korea. The main questions it aims to answer are:

• Does decentralized elements feasible in Korea?
• Does Mastic gum alleviates symptoms and modifies stool microbiome in Korean patients with functional dyspepsia?

The trial aims to evaluate decentralized elements in South Korea, including clinical laboratory testing using local laboratories, medication adherence assessment using wearable devices, analysis of self-kit specimens, delivery and tracking of investigational medication, real-time remote interview of subjects and e-consent acquisition.

Mastic gum is registered with the Ministry of Food and Drug Safety in South Korea as a dietary supplement for gastric health, and the study aims to explore the effect on the gastrointestinal symptoms and composition of the stool microbiome.

1) Inclusion Criteria

1. Adults aged 19 to 75 years old at the time of consent.
2. The sum of the intensity and frequency score of the six major symptoms (epigastric pain, early satiety, postprandial fullness, bloating, belching and nausea) of the self-evaluation questionnaire for dyspepsia (SEQ-DYSPEPSIA) is 12 or more.

2) Exclusion Criteria

1. Those with symptoms (dysphagia, severe dysphagia, bleeding, weight loss, anemia, bloody stools) that may suggest a malignant disease of the gastrointestinal tract.
2. Subjects with a diagnosis of eosinophilic esophagitis or a history of eosinophilic esophagitis.
3. Have or have had clinically significant hepatic, renal, neurologic, respiratory, endocrine, hematologic and oncologic, cardiovascular, urinary, or psychiatric disease.
4. Pregnant or lactating women
5. Have or have had a history of clinically significant hypersensitivity to the dietary supplement to be administered.
6. Aspartate aminotransferase or alanine aminotransferase greater than 5 times the upper limit of normal range on screening tests
7. Subjects who are expected to take other medications within the study period that may affect the evaluation of the effectiveness of the study substance (gastrointestinal motility promoters, acid secretagogues, proton pump inhibitors, nonsteroidal anti-inflammatory drugs, anticholinergics, erythromycin, corticosteroids, antidepressants, etc.
8. Those deemed by the investigator to be unsuitable for participation in the clinical trial due to other reasons.