Oral Lactobacillus Reuteri for Skin Barrier Dysfunction in Obesity

Inclusion Criteria: * 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 Exclusion Criteria: * 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