Interdigestive myoelectric complex in germ-free rats

The effect of intestinal bacteria on the interdigestive myoelectric complex (IDMEC) was studied by recordings of the electrical activity of the proximal and distal small bowel in fasting germ-free (n = 6), gnotobiotic (n = 7), and conventional (n = 6) rats in vivo. Germ-free and gnotobiotic rats were operated and studied in germ-free or gnotobiotic conditions. The IDMEC period (mean +/- SD) in the proximal and distal small bowel was significantly longer in germ-free rats (20 +/- 2 min and 102 +/- 14 min) as compared to conventional rats (13 +/- 1 min and 58 +/- 5 min). Association of germ-free rats with a limited flora (gnotobiotic rats) decreased the IDMEC period significantly (15 +/- 1.5 min and 75 +/- 14 min). The migration velocity of the IDMEC was inversely related to the IDMEC period. These observations confirm previous data suggesting that the interdigestive motor complex has a role in the homeostasis of the bacterial content of the small bowel.