Characteristics of healthy and Androgenetic Alopecia scalp micriobiome: Effect of Lindera strychnifolia roots extract as a natural solution for its modulation.

Objective The human scalp harbours a vast community of microbiotal mutualists. Androgenetic alopecia (AGA), the most common form of hair loss in males, is a multifactorial condition involving genetic predisposition and hormonal changes. The role of microflora during hair loss remains to be understood. After having characterized the scalp microbiota of 12 healthy male subjects and 12 AGA male subjects (D0), the aim of this investigation was to evaluate the capacity ofLindera strychnifoliaroot extract (LsR) to restore a healthy bacterial and fungal scalp microflora after 83 days (D83) of treatment. Material and methods The strategy used was based on high-throughput DNA sequencing targeting the encoding 16S ribosomal RNA for bacteria andInternal Transcribed Spacer 1ribosomal DNA for fungi. Results Test analysis of relative abundance comparing healthy and AGA subjects showed a significant increase ofCutibacterim acnes(P < 0.05) andStenotrophomonas geniculata(P < 0.01) in AGA subjects. AGA scalp condition was also associated with a significant (P < 0.05) decrease ofStaphylococcus epidermidisrelative abundance. A lower proportion ofMalasseziagenus in samples corresponding to AGA scalps and an increase of other bacterial genera (Wallemia,Eurotium) were also noted. At the species level, mean relative abundance ofMalassezia restrictaandMalassezia globosawere significantly lower (P < 0.05) in the AGA group. Eighty-three days of treatment induced a significant decrease in the relative abundance ofC. acnes(P < 0.05) andS. geniculata(P < 0.01).S. epidermidisincreased significantly (P < 0.05). At the same time, LsR treatment induced a significant increase in the proportion ofM. restrictaandM. globosa(P < 0.05). Conclusion Data from sequencing profiling of the scalp microbiota strongly support a different microbial composition of scalp between control and AGA populations. Findings suggest that LsR extract may be a potential remedy for scalp microbiota re-equilibrium.