Microbial Colonization, Skin Barrier to Water Loss
Conditions
Brief summary
This clinical trial aims to evaluate the safety and efficacy of oral Bifidobacterium longum supplementation for treating obesity-induced skin barrier impairment in individuals aged 18-40 with BMI ≥30, compared to healthy controls. The study focuses on the following questions: Can oral Bifidobacterium supplementation reduce skin barrier damage (measured by transepidermal water loss/TEWL) in obese participants? Does modulation of gut microbiota with Bifidobacterium longum impact skin barrier function and systemic inflammation? Researchers will compare outcomes across two groups: * Intervention Group (Obese): Oral Bifidobacterium longum capsules * Placebo Control Group (Obese): Oral inactive Bifidobacterium longum (heat-killed) Participant Procedures: Take daily oral capsules (Bifidobacterium longum or inactive strain) for 4 weeks Undergo non-invasive skin testing (TEWL measurements) at baseline and study completion Provide blood, stool, and skin swab samples for inflammation and microbiome analyses Complete weekly check-ins to report adverse effects (e.g., gastrointestinal discomfort, skin irritation)
Interventions
BIOLOGICALOral administration of inactive Bifidobacterium longum group
1×10\^11 CFU of inactive Bifidobacterium longum was given orally once daily for one month
BIOLOGICALOral Bifidobacterium longum group
1×10\^11 CFU of Bifidobacterium longum was given orally once daily for one month
Sponsors
Shenzhen People's Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mean change in transepidermal water loss (TEWL, g/h/m²) on the volar forearm from baseline to 1 month after intervention, measured by Tewameter | Baseline through 1 month after intervention | TEWL will be assessed on the volar aspect of the forearm using a Tewameter device under standardized environmental conditions (controlled temperature and humidity). At each time point, TEWL will be measured at three predefined skin sites on the volar forearm, and the average value will be used. The primary outcome will be the mean change in TEWL (g/h/m²) from baseline (Day 0) to 1 month after intervention. Lower TEWL values indicate improved skin barrier function. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in body weight and BMI | Baseline through 1 month after intervention | Participants' body weight (kg) and BMI (kg/m²) will be recorded at baseline and post-intervention. Data will be reported as mean change. |
| Change in gut Bifidobacterium longum abundance and metabolites in fecal samples | Baseline through 1 month after intervention | Stool samples will be collected at baseline and after intervention. Microbial abundance will be assessed by 16S rRNA sequencing, and metabolites will be profiled using targeted metabolomics. Data will be reported as relative abundance (%) and metabolite concentrations (µM). |
| Change in serum inflammatory cytokine levels | Baseline through 1 month after intervention | Serum samples will be collected before and after Bifidobacterium longum treatment. Cytokine levels (e.g., IL-6, TNF-α, IL-22) will be measured by ELISA, reported as pg/mL. |
| Change in skin hydration measured by Corneometer | Baseline through 1 month after intervention | Skin hydration will be assessed using a Corneometer device. Outcomes will be expressed as mean skin capacitance values (arbitrary units) at baseline and post-intervention. |
| Change in clinical skin health score | Baseline through 1 month after intervention | Skin dryness, scaling, erythema, itching, and allergy-related symptoms will be evaluated using a standardized Skin Dryness Scoring System. Data will be reported as mean score change from baseline. |
Countries
China
Outcome results
None listed