Olivier Lesouhaitier

With a view to reducing the impact of Cutibacterium acnes ( C . acnes ) on acne vulgaris, it now appears interesting to modify the balance between acneic and non‐acneic strains of C . acnes using moderate approach. In the present study, we identified that a G2 dendrigraft of lysine dendrimer (G2 dendrimer) was able to modify membrane fluidity and biofilm formation of a C . acnes acneic strain (RT5), whereas it appeared no or less active on a C . acnes non‐acneic strain (RT6). Moreover, skin ex vivo data indicated that the G2 is able to decrease inflammation (IL1α and TLR‐2) and improve skin desquamation after of C . acnes acneic strains colonization. Then, in vivo data confirmed, after C . acnes quantification by metagenomic analysis that the G2 cream after 28 days of treatment was able to increase the diversity of C . acnes strains versus placebo cream. The data also showed a modification of the balance expression between C . acnes phylotype IA1 and phylotype II abundances. Taken together, the results confirm the interest of using soft compounds in cosmetic product for modifying phylotype abundances and diversity of C . acnes strains could be a new strategy for prevent acne vulgaris outbreak.