The 2026 BMJ Open protocol tests combined oral probiotics plus topical secretome for clinical improvement and microbiome restoration in acne vulgaris. For adults with persistent acne, it sets out trial design and microbiome endpoints but reports no efficacy results. Secretome here means the mixture of molecules secreted by mesenchymal stem cells, applied as a topical ingredient alongside drugs and probiotics.
Persistent acne in adulthood is common. MDedge Dermatology reports up to 50% of patients have acne persisting into adulthood, including 50.9% of women aged 20-29 and 35.2% aged 30-39. That pattern makes adult eligibility and standard-care options central to reading this protocol.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- Who does the protocol enroll?
- What combination is being tested?
- What did earlier probiotic research show?
- Why is secretome use still experimental?
- What treatments do guidelines recommend now?
Who does the protocol enroll?
The protocol enrolls people with dermatologist-diagnosed mild-to-moderate facial acne, including adults with persistent acne, as described by BMJ Open in the trial protocol. Severity uses Lehmann counts rather than symptoms alone.
Readers can check the basic categories quickly: These cutoffs matter because comedones, papules, and pustules respond differently to treatment. A person near a boundary may fall into a different group after one flare.
- Mild: fewer than 20 comedones or fewer than 15 papules or pustules
- Moderate: 20-100 comedones and 20-50 papules or pustules
- Location: facial acne diagnosed by a dermatologist
What combination is being tested?
The experimental arm combines an oral probiotic, nightly prescription cream, and topical secretome. BMJ Open lists oral HEXBIO granules with six strains, including Lactobacillus acidophilus BCMC 12130, L. casei BCMC 12313, and Bifidobacterium longum BCMC 02120.
The topical plan adds nightly clindamycin-tretinoin cream plus secretome. This is a combination design, not a test of probiotics alone. Any future change in lesions or microbes would reflect the full regimen. Readers should not read strain names as proof that those strains treat acne.
What did earlier probiotic research show?
Earlier oral-probiotic evidence is small and narrow. A 12-week randomised, double-blind, placebo-controlled trial in 74 patients aged 12-30 found Acne Global Severity Scale improvement in 50% on probiotic versus 29.4% on placebo, p=0.03, according to the PMC/JAMA Dermatology study in the 74-patient trial report. That result is short-term and limited to a young, small sample.
The new protocol therefore starts from an open question rather than an established benefit. Adults with persistent disease were poorly represented in that prior sample. Microbiome restoration also remains a measured endpoint, not a proven clinical gain.
Why is secretome use still experimental?
Regulatory status is a key limit. A 2025 PMC narrative review states that no MSC-derived secretome or exosome product has received FDA or EMA approval for dermatologic use, citing unstandardized isolation, manufacturing variability, and limited potency assays in the secretome review. Approval here means formal marketing authorization for skin disease, not sale as cosmetics.
Dermatology Times adds practical context: the 2026 protocol reports design and microbiome endpoints only, and U.S. therapeutic exosome use is lawful only under an FDA Investigational New Drug trial. Social-media skin-care claims do not carry the same controls as trial manufacturing and oversight.
What treatments do guidelines recommend now?
U.S. standard care remains conventional drugs. The American Academy of Dermatology's 2024 guidance strongly recommends topical benzoyl peroxide, retinoids, and antibiotics or fixed combinations, plus oral isotretinoin for severe acne, not probiotics or secretome, according to the Academy report in the acne guideline summary.
Those options have dosing, safety, and combination rules familiar to dermatologists. For an adult with persistent mild-to-moderate acne, the practical step is a dermatologist visit with a lesion history, prior retinoid or antibiotic use, and pregnancy plans. Bring photos of flares and a list of current topicals. Ask whether a guideline-based regimen fits before considering any trial referral.
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