Probiotic Bacteria Induce a ‘Glow of Health’
(A) Quiescent (telogen-phase) hair follicles predominate in control-diet fed C57BL/6 mice. In contrast, the majority of the hair follicles are active (anagen-phase) in probiotic-fed mice of the same age. Active hair follicles undergoing rapid growth exhibit numerous proliferating cells (ki-67+). More rarely the regressing stage (catagen) contain caspase-3+ apoptotic cells. Control Telogen and Probiotic Anagen: Hematoxylin and Eosin. Probiotic Anagen-ki-67 and Probiotic Catagen-caspase-3: DAB chromogen, Hematoxylin counterstain. Bars = 50 µm. Classification of fifty intact longitudinally-sectioned hair follicles per treatment group were evaluated according to their stage of cycling (in B and C below). The distribution pattern of hair-follicle staging differs significantly (P<0.0001) among probiotic- and control diet-fed (B) male and (C) female mice. Numbers on the y-axis of bar graphs represent the mean±SEM of hair-follicles classified in each hair cycle stage. The % percentage of hair follicles in telogen (T), anagen (A) or catagen (C) stage is illustrated in circular graphs. Probiotic-fed mice of both genders show an anagen stage predominance. (D) Dietary supplementation with probiotics lead to a significant (P<0.0001) increase of sebocytes in skin pilosebaceous units. The y-axis stands for the mean±SEM of sebocyte counts per X20 high power field image. (E) The quantitative assessment of cellular proliferation in sebaceous glands with ki-67-specific immunohistochemistry (circular image) reveals that dietary probiotics increase the proliferative capacity of sebocytes. Numbers on the y axis of bar graphs correspond to the mean±SEM of the index of proliferating sebocytes per total number of sebocytes in x40 high power fields. Circular image: DAB chromogen, Hematoxylin counterstain. Bar = 25 µm.