Effect of Primary Biotin Deficiency on the Skin of Germ-Free and Conventional Mice Fed a Purified Biotin-Deficient Diet Without Supplementation with Egg White

The study investigated the effects of primary biotin deficiency on growth and skin in germ-free and conventional mice over 57 days. Germ-free mice on a biotin-deficient diet showed significant body weight reduction and severe alopecia, unlike conventional mice. Both groups experienced decreased biotin levels and pyruvate carboxylase activity in various tissues, with germ-free mice showing lower activity levels. Histological analysis revealed degeneration in the hair medulla and cortex in germ-free mice, leading to hair root downgrowth.