The Role of Intestinal Flora in Biotin Deficiency in Conventional and Germ-Free Mice Fed a Purified Biotin-Deficient Diet without Supplementation with Egg White.

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.

“…However, primary biotin deficiency using germ-free mice has not yet been reported clearly from the viewpoint of alopecia and growth depression. Previously, we showed that some germ-free mice fed a biotin-deficient diet without inclusion of egg white for 20 days exhibited alopecia, but not growth depression [6]. However, the body weight in rats has been reported to decrease significantly after 50 to 60 days under conditions comparable to those used in our previous experiments [4].…”

“…In the present study, significant differences in weight gain were observed in germ-free mice at 57 days between control and biotin-deficient groups, although the decrease in weight gain of the deficient germ-free mice was less than that in the biotin-deficient rats [4], suggesting that in mice fed a biotin-deficient diet, growth retardation takes place gradually. This may explain why no reduction in body weight was observed during the short experimental period of our previous study [6]. The decrease in biotin level and in pyruvate carboxylase activity in tissues also indicates that the degree of biotin deficiency was severer in germ-free mice fed the biotin-deficient diet than in conventional ones.…”

“…In our previous study, some germ-free mice fed the biotin-deficient diet for 20 days exhibited partial alopecia [6], whereas biotin deficiency in the germ-free mice in the present study was more severe, with most animals exhibiting alopecia. Severe alopecia was observed on the whole back from about 40 days, but at 57 days the whole back was covered sometimes with new fine hair resembling a hen with a molted plume.…”

“…Egg white contains constituents other than avidin that could be involved in growth depression such as ovoinhibitor proteins and ovomucoids, both of which act as trypsin inhibitors [1 ] . In our previous study [6], some germ-free mice fed a biotin-deficient diet without inclusion of egg white for 20 days exhibited partial alopecia, but not growth depression. However, Cherruau et al [4] had reported that biotin deficiency was easily induced in germ-free rats and that the body weight in rats decreased significantly after 50 to 60 days under conditions similar to ours.…”

“…Lighting was regulated automatically to provide constant periods of alternating light and darkness (the light was on from 8:00 to 20:00). The composition of the control diet used in this experiment was as reported previously [6]. The biotin-deficient diet had the same composition as the control diet except that no biotin was added.…”