It has been confirmed that treatment with Shenqu Xiaoshi Oral liquid (SXOL) effectively improves dyspeptic symptoms and is well tolerated. It is not inferior to domperidone syrup and leads to sustained improvement in Chinese children with functional dyspepsia (FD). This study aims to evaluate the possible regulatory effect of SXOL on intestinal microbiome in children with FD, further exploring its related mechanism.

Inclusion Criteria:

1. Outpatients aged 3-14 years old;
2. Meeting ≥1 condition(s): (1)Postprandial fullness;(2)early satiation;(3)Epigastric pain or burning not associated with defecation;
3. Having symptoms at least 2 months and at least 4 days per month before diagnosis;
4. During the 2-wk lead-in period, no relevant drugs for the treatment of dyspepsia and anorexia were used, good eating habits have been established, and the FD symptoms still existed (symptom score≥3).
5. Informed consent was obtained from the parents/guardians of the participant. If the child was more than 8 years old, additional informed consent would be required from the participant.

Exclusion Criteria:

1. Anorexia and dyspepsia caused by certain drugs and confirmed organic diseases such as erosive gastritis, peptic ulcer, etc;
2. Severe malnutrition;
3. Serious primary diseases of the cardiovascular, nervous, respiratory, hepatobiliary and endocrine systems;
4. Mental disorders, intellectual disabilities, and/or communication impairments;
5. Lactose intolerant or allergic to the ingredients of Shenqu Xiaoshi Oral Liquid or Traditional Chinese medicine;
6. Probiotics or antibiotics within 4-wk;
7. Participated in a clinical trial within the past 12-wk;
8. Individuals deemed unsuitable for this clinical trial.