Figure 1. Slower intestinal transit during aging in mice. The ink propulsion distance was illustrated in different age groups (A). The length of small intestine was extended (B) while in vivo intestinal propulsion rate was reduced (C) during aging. Statistical analysis was performed using one-way analysis of variance and data were represented as mean ± SD, statistical significance is: ### P < 0.001 compared with 2-mo-old group; ** P < 0.01, *** P < 0.001 compared with previous group; n=8 mice per group.