IGF1 and Insulin resistance: Some Lactobacillus strains have been found to reduce sebaceous triglyceride levels, enhance skin hydration, upregulate the expression of the moisturizing factor ceramide, inhibit Propionibacterium acnes proliferation, ameliorate insulin resistance, normalize IGF-1 gene expression, and improve epidermal barrier function (Gueniche et al., 2010; Fabbrocini et al., 2016; Kim et al., 2021; Tsai et al., 2021).