Investigating the causal relationship between skin microbiota and hypertrophic scar using bidirectional mendelian randomization.

Summary

Using bidirectional two-sample Mendelian randomization with PopGen and FinnGen GWAS, the study found protective causal effects of Enhydrobacter, Micrococcus, and Acinetobacter (moist skin) and increased risk from Finegoldia and Lactobacillales (dry skin) for hypertrophic scars. Sensitivity analyses showed no horizontal pleiotropy or heterogeneity.

Key Findings

• Bidirectional MR identified protective causal effects of Enhydrobacter, Micrococcus, and Acinetobacter on moist skin against hypertrophic scar.
• Finegoldia and Lactobacillales on dry skin were causally linked to increased hypertrophic scar risk.
• Sensitivity analyses (MR-Egger intercept, Cochrane’s Q) found no evidence of horizontal pleiotropy or heterogeneity.

Clinical Implications

Suggests targeting specific taxa through topical probiotics, prebiotics, or antimicrobial stewardship may modulate HS risk, and motivates microbiome-informed postoperative scar care.

Limitations

• GWAS-based microbiota proxies provide limited taxonomic resolution and may not capture strain-level effects.
• Clinical translation requires validation in prospective cohorts and interventional studies.

Future Directions

Prospective validation linking skin microbiome profiles to HS incidence and trials testing microbiome modulation (e.g., topical probiotics) in high-risk patients.