Probiotic Microbes Sustain Youthful Serum Testosterone Levels and Testicular Size in Aging Mice
a. Representative histology of Swiss mice testes at the age of 12 months. Leydig cell areas in the testicular interstitium of probiotic-fed mice are of increased size compared to the corresponding areas of control mice. Hematoxylin and eosin. Bars = 100 µm b. Histomorphometrical counts of Leydig cell areas at different time-points revealed the statistical significance of the L. reuteri effect. Numbers on the y-axis of bar graphs correspond to the mean±SEM of Leydig area size. c. Point-counting stereology counts reveal that L. reuteri-fed mouse testes have significantly increased nuclear volumes and an increased number of Leydig cells per testis. Numbers on the y axis of bar graphs correspond to the mean±SEM of “Nuclear volume of germ cells per unit area” or the “absolute nuclear volume of germ cells”; *p<0.05, **p<0.001, ***p<0.0001.