Retrospective Cohort Study on Asthma With Frequent Acute Attacks Phenotype

Inclusion Criteria: 18-65 years old, taking asthma medication for at least 4 weeks. The diagnostic criteria for asthma are based on the recommendations of the current guidelines (Guidelines for the Prevention and Treatment of Bronchial Asthma (Version 2020), as follows: 1. Repeated episodes of wheezing, shortness of breath, chest tightness, or coughing are often associated with exposure to allergens, cold air, physical and chemical stimuli, viral upper respiratory tract infections, and exercise. 2. During the attack, scattered or diffuse wheezing sounds can be heard in both lungs, mainly in the expiratory phase, and the expiratory phase is prolonged. 3. The above symptoms and signs can be alleviated by treatment or spontaneously. 4. Except for wheezing, shortness of breath, chest tightness, and coughing caused by other diseases. 5. Those with atypical clinical manifestations (such as no obvious wheezing or physical signs) should have at least one positive pulmonary function test as follows: 1. Positive bronchial provocation test or exercise provocation test; The positive FEV1 of bronchodilator test increased by ≥ 12%;, And the absolute value of FEV1 increase ≥ 200ml; 3. Peak expiratory flow (PEF) intraday (or 2-week) variability ≥ 20%. Asthma can be diagnosed if it meets the criteria of 1-4 or 4-5. Exclusion Criteria: 1. Complicated with pneumonia, pulmonary interstitial fibrosis, active pulmonary tuberculosis, obstructive sleep apnea hypopnea syndrome, and other respiratory system related diseases, with a previous history of lung surgery; 2. Those with the following diseases or conditions: severe, progressive, or uncontrolled cardiovascular, liver, kidney, hematopoietic, and neurological disorders; Malignant tumor; Or the presence of immunosuppression (including the use of immunosuppressants or HIV infection resulting in low immune function); 3. Accompanied by severe gastrointestinal diseases (such as inflammatory bowel disease \[IBD\] or irritable bowel syndrome \[IBS\]), severe diarrhea (watery stools more than 3 times and lasting for more than 3 days) and constipation (less than 2 stools per week and accompanied by difficulty in defecation) in the past 3 weeks; 4. Systematic application of antibiotics, systemic glucocorticoids (including oral, intravenous \[IV\] or intramuscular \[IM\]), microecological agents, or traditional Chinese medicine within the past 4 weeks; 5. Excessive obesity (BMI\>32.0 kg/m2), pregnant and lactating women; 6. Poor compliance, unable to cooperate with clinical observation and specimen collection.