Objective of this clinical trial:

The goal of this clinical study is to evaluate whether an environmental probiotic spray can improve symptoms in adults with cat allergy-induced allergic rhinitis (AR) and allergic asthma (AA). It will also assess the safety of the probiotic spray. The main questions it aims to answer are:

Does the environmental probiotic spray reduce the severity of nasal and asthma symptoms in participants? Are there any adverse effects observed in participants using the probiotic spray? Researchers will compare the environmental probiotic spray group to a placebo group (a look-alike spray containing no active ingredients) to determine if the probiotic spray is effective in managing allergic rhinitis and asthma symptoms.

Participants will:

Receive the environmental probiotic spray or placebo daily for 3 months Attend monthly clinic visits for checkups and assessments Undergo a final evaluation at 3 months, including symptom scoring and safety checks

Key Assessments:

Total Nasal Symptom Score (TNSS) for allergic rhinitis Asthma Control Test (ACT) score for allergic asthma

Inclusion Criteria:

• Age 18-70 years；
• Diagnosed with cat allergy (cat dander-specific IgE level ≥ class 2: > 0.7 IU/mL) and allergic rhinitis with or without allergic asthma;
• Residing in the same living environment for at least 3 months (and no plans to change residence within the next 6 months);
• Patients receiving conventional symptomatic treatment.

Exclusion Criteria:

• Presence of other severe systemic diseases;
• Residence duration < 3 months or plans to change residence within the next 6 months;
• Pregnancy;
• Current or planned use of biologic therapy;
• Any other condition that, in the investigator's judgment, may pose significant risks to the participant if enrolled in the study.