Hair Growth Promoting Effects of Limosilactobacillus reuteri Isolated from Honeybee through Wnt/β-catenin Signal Transduction

In this study, Limosilactobacillus reuteri (L. reuteri) NCHBL-005 isolated from the midgut of honeybees was isolated and a formulation was manufactured to develop new materials and products that alleviate and prevent hair loss. L. reuteri NCHBL-005 did not induce cytotoxicity in human follicle dermal papilla cells (HFDPCs). It increased the mRNA of hair growth-related genes HGF, IGF1, and VEGF in HFDPCs, and decreased the mRNA expression of DKK1, an inhibitory factor that induces the transition from the anagen phase to the telogen phase. In mice, L. reuteri NCHBL-005 exhibited a hair-promoting effect, increasing the number and size of hair follicles. In addition, L. reuteri NCHBL-005 did not show any significant effect on the expression of 5α-reductase-related genes (SRD5A1, SRD5A2, SRD5A3) in HFDPCs. The effect of L. reuteri NCHBL-005 on the activation of the Wnt/β-catenin signaling pathway in HFDPCs was observed, and the expression levels of Wnt3a, Wnt5a, and Wnt10b were increased in a concentration-dependent manner. Therefore, the hair growth promoting effect of L. reuteri NCHBL-005 may be mediated by a novel mechanism via a non-androgenic pathway rather than a traditional hair loss suppression mechanism such as androgen signaling inhibition. It was suggested that hair growth may be induced by activating the Wnt/β-catenin signaling pathway by upregulating the expression of several Wnt ligands and promoting the proliferation and differentiation of hair follicle stem cells.