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RecruitingNCT07834138FACEMICROUpdated Oct 1, 2026

Facial Skin Microbiome in Patients With Moderate-to-Severe Acne Vulgaris Treated With Isotretinoin

An observational study in Acne Vulgaris, sponsored by Can Tho University of Medicine and Pharmacy. Recruiting at 1 site in Vietnam. Open to participants aged 16 Years to 35 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-01.

Sponsored by Can Tho University of Medicine and Pharmacy · Observational

From the registry’s dates

  • Started Jan 2026; still recruiting 9 months later.
Updated Oct 1, 2026Eligibility revisedGo to Updates ↓
Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
90
Ages
16 Years to 35 Years
Sex
All
01

Study summary

Acne vulgaris is associated with changes in the facial skin microbiome, but longitudinal microbiome changes during isotretinoin therapy remain incompletely understood. This prospective observational cohort study aims to characterize the facial skin microbiome in patients with moderate-to-severe acne vulgaris before and during isotretinoin treatment and to compare microbiome profiles with healthy individuals.

Participants with moderate-to-severe acne vulgaris receiving standard-of-care oral isotretinoin will be followed prospectively. Facial skin swab samples will be collected before treatment and at scheduled follow-up visits during therapy. Healthy volunteers without acne will provide a single facial skin swab for comparison. Bacterial communities will be analyzed using 16S rRNA gene sequencing, and clinical severity will be assessed using validated acne severity scores and lesion counts.

The study will evaluate changes in microbial diversity, bacterial composition, and the relative abundance of acne-associated microorganisms during isotretinoin treatment. Associations between microbiome changes and clinical improvement will also be explored. Results are expected to improve understanding of the role of the skin microbiome in acne and provide evidence for future microbiome-based therapeutic strategies.

Read the detailed description

Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit and is one of the most common dermatologic disorders worldwide. Increasing evidence suggests that acne is associated with alterations in the composition and diversity of the skin microbiome rather than the presence of a single pathogenic microorganism. However, longitudinal changes in the facial skin microbiome during isotretinoin treatment have not been fully characterized in Southeast Asian populations.

This study is a prospective observational cohort conducted in Vietnam. The study includes two participant groups: patients with moderate-to-severe acne vulgaris and healthy volunteers without acne. Patients receive oral isotretinoin according to routine clinical practice and institutional treatment protocols. The study does not assign or modify treatment; investigators prospectively observe clinical and microbiome changes during routine care.

Facial skin samples are collected using standardized skin swab procedures from predefined facial sites. Samples are processed for bacterial DNA extraction and 16S rRNA gene sequencing to characterize microbial communities. Sequencing data are analyzed using bioinformatics pipelines for taxonomic classification and diversity analysis.

Clinical assessments include validated acne severity grading systems, inflammatory and non-inflammatory lesion counts, and evaluation of treatment response during follow-up. Healthy volunteers provide baseline microbiome samples for comparison with acne participants before treatment.

The primary objective is to characterize longitudinal changes in the facial skin microbiome during isotretinoin treatment in patients with moderate-to-severe acne vulgaris. Secondary objectives include comparing baseline microbiome characteristics between acne patients and healthy individuals and exploring associations between microbiome composition and clinical treatment outcomes.

Study findings may contribute to a better understanding of microbiome dynamics during isotretinoin therapy and provide a foundation for future microbiome-targeted approaches in acne management.

02

Conditions studied

  • Acne Vulgaris

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Keywords

  • Skin microbiome
  • Facial microbiome
  • Isotretinoin
  • 16S rRNA sequencing
  • Cutibacterium acnes
  • Bacterial diversity
  • Microbial dysbiosis
03

In context

Acne Vulgaris

790 studies on the registry are indexed under Acne Vulgaris; 93 are open to participants now.

This study's planned enrollment of 90 is close to the median of 88 across 95 observational studies indexed under Acne Vulgaris.

Browse Acne Vulgaris studies →

Lead sponsor

Can Tho University of Medicine and Pharmacy is the lead sponsor of 35 studies on the registry; 8 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

The criteria were revised on the registry on Oct 1, 2026. See what changed

Ages eligible
16 Years to 35 Years
Sexes eligible
All
Accepts healthy volunteers
Yes
Sampling method
Non-probability sample

Study population

The study population consists of participants aged 16 to 35 years recruited at Can Tho University of Medicine and Pharmacy Hospital. The study includes patients with acne vulgaris who are indicated for oral isotretinoin treatment and healthy volunteers without acne vulgaris. The acne cohort is followed prospectively during isotretinoin treatment, while the healthy control group is assessed at baseline for comparison of facial skin microbiome characteristics.

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

Acne Vulgaris Cohort:

  • Participants aged 16-35 years.
  • Clinical diagnosis of acne vulgaris.
  • Presence of acne lesions on both cheeks.
  • Indication for oral isotretinoin treatment according to clinical assessment at Can Tho University of Medicine and Pharmacy Hospital.
  • Willingness to participate in the study.

Healthy Control Cohort:

  • Voluntary participation in the study.
  • No history or clinical manifestations of acne vulgaris.
  • No use of antibiotics or isotretinoin within the previous 6 months.
  • No lesions of other skin diseases on the face.

Exclusion criteria

Exclusion Criteria:

  • Current dermatologic diseases such as rosacea, contact dermatitis, eczema, or psoriasis.
  • Current acute or chronic medical diseases.
  • Use of antibiotics or isotretinoin within the previous 3 months.
  • Use of phototherapy or topical probiotics on the facial skin within the previous 3 months.
  • Use of facial cleansing products or topical medications within 24 hours before sample collection.
  • History of allergy.
  • Unwillingness to participate in the study.
05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
90 participants (estimated)
Patient registry
No

Groups and cohorts

  • Acne Vulgaris Cohort

    Participants with moderate-to-severe acne vulgaris who are receiving oral isotretinoin as part of routine clinical care and are followed prospectively for clinical and facial skin microbiome changes

    Drug: ISOtretinoin 10 MG

  • Healthy Control Cohort

    Healthy volunteers without acne vulgaris who provide baseline facial skin samples for comparison with the acne vulgaris cohort.

Interventions

  • DrugISOtretinoin 10 MG

    Oral isotretinoin administered as part of routine clinical care according to institutional treatment protocols. The study does not assign or modify isotretinoin treatment; investigators prospectively

06

What researchers measure

Primary outcomes

  1. Shannon-Wiener Diversity Index of the Facial Skin Microbiome at Baseline

    Difference in the Shannon-Wiener diversity index of the facial skin microbiome between participants with moderate-to-severe acne vulgaris and healthy controls at baseline.

    Time frame: At baseline, before isotretinoin treatment in the acne cohort

  2. Change in Shannon-Wiener Diversity Index of the Facial Skin Microbiome During Isotretinoin Treatment

    Change in the Shannon-Wiener diversity index of the facial skin microbiome from baseline to after 20 weeks of isotretinoin treatment in participants with moderate-to-severe acne vulgaris.

    Time frame: Baseline to Week 20

Secondary outcomes

  1. Relative Abundance and Taxonomic Composition of the Facial Skin Microbiome

    Comparison of bacterial community composition at the phylum and genus levels between the acne vulgaris and healthy control cohorts at baseline.

    Time frame: Baseline

  2. Change in Simpson Diversity Index During Isotretinoin Treatmen

    Change in the Simpson diversity index of the facial skin microbiome from baseline to Week 20 in participants receiving oral isotretinoin.

    Time frame: Baseline to Week 20

  3. Chao1 Richness Index of the Facial Skin Microbiome at Baseline

    Comparison of the Chao1 richness index of the facial skin microbiome between the acne vulgaris and healthy control cohorts at baseline.

    Time frame: Baseline

  4. ACE Richness Index of the Facial Skin Microbiome at Baseline

    Comparison of the ACE richness index of the facial skin microbiome between the acne vulgaris and healthy control cohorts at baseline.

    Time frame: Baseline

  5. Jaccard Distance of the Facial Skin Microbiome at Baseline

    Comparison of Jaccard distance of the facial skin microbiome between the acne vulgaris and healthy control cohorts at baseline.

    Time frame: baseline

  6. Bray-Curtis Dissimilarity of the Facial Skin Microbiome at Baseline

    Comparison of Bray-Curtis dissimilarity of the facial skin microbiome between the acne vulgaris and healthy control cohorts at baseline.

    Time frame: Baseline

  7. Unweighted UniFrac Distance of the Facial Skin Microbiome at Baseline

    Comparison of unweighted UniFrac distance of the facial skin microbiome between the acne vulgaris and healthy control cohorts at baseline.

    Time frame: Baseline

  8. Weighted UniFrac Distance of the Facial Skin Microbiome at Baseline

    Comparison of weighted UniFrac distance of the facial skin microbiome between the acne vulgaris and healthy control cohorts at baseline.

    Time frame: Baseline

  9. Change in Relative Abundance of Bacterial Taxa at the Phylum Level From Baseline to Week 20

    Change in the relative abundance of bacterial taxa at the phylum level in facial skin microbiome samples from baseline to Week 20 in participants receiving oral isotretinoin.

    Time frame: Baseline to Week 20

  10. Change in Relative Abundance of Bacterial Taxa at the Genus Level From Baseline to Week 20

    Change in the relative abundance of bacterial taxa at the genus level in facial skin microbiome samples from baseline to Week 20 in participants receiving oral isotretinoin.

    Time frame: Baseline to Week 20

  11. Change in the Number of Amplicon Sequence Variants Detected From Baseline to Week 20

    Change in the number of amplicon sequence variants detected in facial skin microbiome samples from baseline to Week 20 in participants receiving oral isotretinoin.

    Time frame: Baseline to Week 20

  12. Change in Simpson Diversity Index From Baseline to Week 20

    Change in the Simpson diversity index of the facial skin microbiome from baseline to Week 20 in participants receiving oral isotretinoin.

    Time frame: Baseline to Week 20

  13. Change in Chao1 Richness Index From Baseline to Week 20

    Change in the Chao1 richness index of the facial skin microbiome from baseline to Week 20 in participants receiving oral isotretinoin.

    Time frame: Baseline to Week 20

  14. Change in ACE Richness Index From Baseline to Week 20

    Change in the ACE richness index of the facial skin microbiome from baseline to Week 20 in participants receiving oral isotretinoin.

    Time frame: Baseline to Week 20

  15. Change in Jaccard Distance From Baseline to Week 20

    Change in Jaccard distance of the facial skin microbiome from baseline to Week 20 in participants receiving oral isotretinoin.

    Time frame: Baseline to Week 20

  16. Change in Bray-Curtis Dissimilarity From Baseline to Week 20

    Change in Bray-Curtis dissimilarity of the facial skin microbiome from baseline to Week 20 in participants receiving oral isotretinoin.

    Time frame: Baseline to Week 20

  17. Change in Unweighted UniFrac Distance From Baseline to Week 20

    Change in unweighted UniFrac distance of the facial skin microbiome from baseline to Week 20 in participants receiving oral isotretinoin.

    Time frame: Baseline to Week 20

  18. Change in Weighted UniFrac Distance From Baseline to Week 20

    Change in weighted UniFrac distance of the facial skin microbiome from baseline to Week 20 in participants receiving oral isotretinoin.

    Time frame: Baseline to Week 20

  19. Clinical Response Rate to Isotretinoin at Week 20

    Proportion of participants classified as having good, fair, moderate, or poor/no clinical improvement after 20 weeks of oral isotretinoin treatment. Good, fair, moderate, and poor/no improvement are defined according to the predefined clinical response criteria in the study protocol.

    Time frame: Week 20

07

Study locations

1 of 1 sites recruiting
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

2 registry updates since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Jan 2026 (actual). Primary completion is estimated for Feb 2027, 12 months after the start.

Of 37 observational studies under Acne Vulgaris, half reached primary completion within 10 months of starting (the median), counting those still running; a quarter within 3 and three quarters within 13. This study's planned 12 months is above that.

How these figures are worked out, and which studies are left out of them.

Registered
Sep 17, 2026
First posted
Sep 22, 2026
StartActual
Jan 13, 2026
Primary completionEst.
Feb 7, 2027
CompletionEst.
Mar 7, 2027
Last update
Oct 1, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
Eligibility
1 inclusion criterion edited
What changed in the criteria
Inclusion criteria
  • EditedParticipants aged 1216-35 years.
Oct 1, 2026
Secondary outcomes
4 edited, 14 added, 2 removed
What changed in the outcomes
  • EditedAlpha DiversityChao1 Richness Index of the Facial Skin Microbiome at BaselineTime frame: Baseline
  • EditedBeta DiversityACE Richness Index of the Facial Skin Microbiome at BaselineTime frame: Baseline
  • EditedChange in Bacterial Community CompositionSimpson Diversity Index During Isotretinoin TreatmentTreatmenTime frame: Baseline to Week 20
  • EditedClinical Response Rate to Isotretinoin at Week 20Time frame: Baseline to Week 20 → Week 20
  • AddedJaccard Distance of the Facial Skin Microbiome at BaselineTime frame: baseline
  • AddedBray-Curtis Dissimilarity of the Facial Skin Microbiome at BaselineTime frame: Baseline
  • AddedUnweighted UniFrac Distance of the Facial Skin Microbiome at BaselineTime frame: Baseline
  • AddedWeighted UniFrac Distance of the Facial Skin Microbiome at BaselineTime frame: Baseline
  • AddedChange in Relative Abundance of Bacterial Taxa at the Phylum Level From Baseline to Week 20Time frame: Baseline to Week 20
  • AddedChange in Relative Abundance of Bacterial Taxa at the Genus Level From Baseline to Week 20Time frame: Baseline to Week 20
  • AddedChange in the Number of Amplicon Sequence Variants Detected From Baseline to Week 20Time frame: Baseline to Week 20
  • AddedChange in Simpson Diversity Index From Baseline to Week 20Time frame: Baseline to Week 20
  • AddedChange in Chao1 Richness Index From Baseline to Week 20Time frame: Baseline to Week 20
  • AddedChange in ACE Richness Index From Baseline to Week 20Time frame: Baseline to Week 20
  • AddedChange in Jaccard Distance From Baseline to Week 20Time frame: Baseline to Week 20
  • AddedChange in Bray-Curtis Dissimilarity From Baseline to Week 20Time frame: Baseline to Week 20
  • AddedChange in Unweighted UniFrac Distance From Baseline to Week 20Time frame: Baseline to Week 20
  • AddedChange in Weighted UniFrac Distance From Baseline to Week 20Time frame: Baseline to Week 20
  • RemovedChange in Alpha Diversity During Isotretinoin TreatmentTime frame: Baseline to Week 12
  • RemovedChange in Beta Diversity During Isotretinoin TreatmentTime frame: Baseline to Week 20
Sep 30, 2026
Show all 2 updates
  1. Oct 1, 2026
    Eligibility 1 inclusion criterion edited
    What changed in the criteria
    Inclusion criteria
    • EditedParticipants aged 1216-35 years.
  2. Sep 30, 2026
    Secondary outcomes 4 edited, 14 added, 2 removed
    What changed in the outcomes
    • EditedAlpha DiversityChao1 Richness Index of the Facial Skin Microbiome at BaselineTime frame: Baseline
    • EditedBeta DiversityACE Richness Index of the Facial Skin Microbiome at BaselineTime frame: Baseline
    • EditedChange in Bacterial Community CompositionSimpson Diversity Index During Isotretinoin TreatmentTreatmenTime frame: Baseline to Week 20
    • EditedClinical Response Rate to Isotretinoin at Week 20Time frame: Baseline to Week 20 → Week 20
    • AddedJaccard Distance of the Facial Skin Microbiome at BaselineTime frame: baseline
    • AddedBray-Curtis Dissimilarity of the Facial Skin Microbiome at BaselineTime frame: Baseline
    • AddedUnweighted UniFrac Distance of the Facial Skin Microbiome at BaselineTime frame: Baseline
    • AddedWeighted UniFrac Distance of the Facial Skin Microbiome at BaselineTime frame: Baseline
    • AddedChange in Relative Abundance of Bacterial Taxa at the Phylum Level From Baseline to Week 20Time frame: Baseline to Week 20
    • AddedChange in Relative Abundance of Bacterial Taxa at the Genus Level From Baseline to Week 20Time frame: Baseline to Week 20
    • AddedChange in the Number of Amplicon Sequence Variants Detected From Baseline to Week 20Time frame: Baseline to Week 20
    • AddedChange in Simpson Diversity Index From Baseline to Week 20Time frame: Baseline to Week 20
    • AddedChange in Chao1 Richness Index From Baseline to Week 20Time frame: Baseline to Week 20
    • AddedChange in ACE Richness Index From Baseline to Week 20Time frame: Baseline to Week 20
    • AddedChange in Jaccard Distance From Baseline to Week 20Time frame: Baseline to Week 20
    • AddedChange in Bray-Curtis Dissimilarity From Baseline to Week 20Time frame: Baseline to Week 20
    • AddedChange in Unweighted UniFrac Distance From Baseline to Week 20Time frame: Baseline to Week 20
    • AddedChange in Weighted UniFrac Distance From Baseline to Week 20Time frame: Baseline to Week 20
    • RemovedChange in Alpha Diversity During Isotretinoin TreatmentTime frame: Baseline to Week 12
    • RemovedChange in Beta Diversity During Isotretinoin TreatmentTime frame: Baseline to Week 20

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT07834138
Lead sponsor
Can Tho University of Medicine and Pharmacy
Responsible party
Sponsor
First posted
Sep 22, 2026
Start date
Jan 13, 2026
Primary completion
Feb 7, 2027 (estimated)
Completion
Mar 7, 2027 (estimated)
Last update
Oct 1, 2026

Study contacts

Tram Thi Bao Pham
Contact
ptbtram@ctump.edu.vn
84 0366 100 241

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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