To evaluate the effectiveness and safety of compound probiotic in shortening the course of illness in children with mycoplasma pneumoniae pneumonia, in comparison with placebo.

Inclusion Criteria:

1. diagnosis of MPP based on typical clinical manifestations (e.g., fever, cough, abnormal pulmonary auscultation), radiographic evidence of pneumonia on chest imaging, and laboratory findings in accordance with current pediatric community-acquired pneumonia guidelines;
2. MP infection was confirmed in nasopharyngeal secretions and serum samples using PCR and ELISA;
3. age between 6 months and 12 years;
4. disease duration less than 2 weeks;
5. written informed consent provided by the guardians.

Exclusion Criteria:

1. Previous history of wheezing;
2. Cardiovascular disease and congenital tracheal dysplasia;
3. pneumonia induced by other causes;
4. Dysplasia of bronchial and pulmonary tracts;
5. premature infants;
6. Combined with immunosuppressive diseases;
7. Presence of mental illness.