Comparison of effects on colonic motility and stool characteristics associated with feeding olestra and wheat bran to ambulatory mini-pigs

The goal of this study was to compare the stool-softening effects of olestr a and wheat bran and to determine if changes in patterns of propagating col onic motility were associated with the observed stool softening. Mini-pigs were fed chow (control) or chow supplemented with olestra (80 g/day) or whe at bran (80 g/day) for four days. Proximal colonic motility was monitored c ontinuously, stool viscosity and fecal output measured daily, and cecal-to- anal transit time determined. Compared to controls, olestra and wheat bran significantly softened stool but had no effect on fecal wet weight or colon ic transit time. Neither olestra nor wheat bran changed the number of propa gating contractions per day, amplitude, motility index, propagation velocit y, or the relative distribution of fast and slow propagating contractions. Our data suggest that the stool-softening effects of olestra and wheat bran are not due to direct stimulation of propagating contractions in the colon of the mini-pig.