Figure 3. B. subtilis treatment produces prokinetic actions on colonic motility.

To investigate the functional effects of B. subtilis R0179 treatment on intestinal motility, two different motility assays were performed at baseline and again after one week of treatment. Whole gut transit time is a non-localized, net motility measure encompassing gastric emptying, small bowel transit, and colonic transit. There was no change in whole gut transit time in vehicle-treated mice (A; n=9) or in mice that received B. subtilis (B; n=10) following a week of treatment. The bead expulsion assay was used to assess bacteria-induced changes in motility localized to the colon, the region of the GI tract that contains the highest numbers and biodiversity of bacteria. There was no change in colonic motility in vehicle-treated mice (D; n=7), but B. subtilis-treated mice (E; n=10) exhibited significantly faster colonic motility times following a week of treatment. Furthermore, there was a significantly different percent change from baseline between B. subtilis and vehicle control treatment groups (C, F). Data are shown as individual animals (A,B,D,E), paired Student’s t-test, or mean ± SEM (C,F), unpaired Student’s t-test. * p < 0.05, ** p < 0.01, *** p < 0.001.