The study aims to investigate the relationship between the small molecule metabolite lysophosphatidylglycerol and asthma clinical features and explore its involvement in asthma pathogenesis.

This study screened LPG as a asthma marker by performing metabolomics of the included asthma patients and normal controls, explored the relationship between LPG and clinical features of asthma (including acute exacerbation, asthma control state, asthma treatment steps，lung function, and inflammatory signals including eosinophils, FeNO and total IgE), and further performed in vitro tests to investigate the specific mechanism of LPG's involvement in asthma inflammation through its influence on Treg function.

Inclusion Criteria:

1. clinical diagnosis of asthma.

Exclusion Criteria:

1. Combined with chronic obstructive pulmonary disease, bronchiectasis, pneumonia, obstructive sleep apnea hypopnea syndrome, malignant tumor
2. Combined with acute and chronic respiratory failure
3. Combined with severe cardiovascular disease
4. Pregnant woman.

Patients with asthma who visited or were hospitalized in the Department of Respiratory and Critical Care Medicine of Peking University Third Hospital, who met the asthma diagnostic criteria proposed in the Bronchial Asthma Prevention and Treatment Guidelines and healthy controls without history or symptoms of chronic respiratory disease, allergic status or other conditions that could affect the outcome.