Lead Sponsor

Shenzhen People's Hospital

Age

18 - 40 years

Sex

ALL

Healthy Volunteers

Yes

•1\. Meets 2020 WHO BMI classification:
•a. Normal weight (18.5-24.9 kg/m²)
•b. Overweight (25-29.9 kg/m²)
•c. Obesity (≥30 kg/m²)
•2\. Presence of skin barrier impairment (e.g., dryness, erythema, desquamation, or itching)
•3\. Age 18-40 years
•4\. Generally good health (no active systemic diseases)
•5\. Able and willing to provide written informed consent
•6\. No use of oral/topical medications or probiotics within 6 months prior
•7\. No active skin disease or traumatic skin lesions

•1\. Known allergy or hypersensitivity to probiotics, placebo, or investigational product
•2\. Active skin disease (e.g., psoriasis, eczema, infection) requiring treatment
•3\. Severe medical conditions:
•a. Cardiopulmonary disease (NYHA class III/IV)
•b. Uncontrolled diabetes (HbA1c \>9%)
•c. Autoimmune disorders
•4\. Pregnant or breastfeeding women
•5\. Any condition that may interfere with protocol compliance (per investigator judgement), including:
•a. Inability to understand study procedures
•b. History of poor clinical trial adherence
•6\. Concurrent participation in other interventional trials