Limosilactobacillus fermentum MF10 promotes hair growth through upregulation of Wnt/β-catenin signaling in C57BL/6 mice

Hair loss is the dysfunction and depletion of hair progenitor cells, leading to hair follicle miniaturization. Oxidative stress and inflammatory responses contribute to hair follicle death, causing hair loss. This study aimed to evaluate the hair growth-promoting capacities of Limosilactobacillus fermentum MF10 (MF10) and MF10-fermented Goji berries in a depilation mouse model. Both treatments were selected because their anti-oxidative and anti-inflammatory properties have been confirmed in vitro. Black coloration in the shaved skin of mice was apparent from day 12 and was the highest in the MF10-treated group. Until day 19, the highest pigmentation was observed in the MF10-treated group, not significantly different from that observed in the finasteride (Fin)-treated group, the positive control. Notably, hair follicle size increased only by the MF10 treatment. Skin Wnt/β-catenin signaling was activated by MF10 through downregulation of p-GSK3B protein expression and accumulation of β-catenin, leading increased serum vascular endothelial growth factor levels only in the MF10 group. Additionally, only MF10 modulated the gut microbial abundance of Duncaniella, which correlated with p-GSK3B protein expression. Overall, our results indicate that L. fermentum MF10-treatment promotes hair growth, and that these effects may be due to gut microbiota activating the skin Wnt/β-catenin signaling.