Effects of Intraduodenal Bile on Interdigestive Gastrointestinal and Gallbladder Motility in Healthy Subjects

Abstract

Background/Aims: The enterohepatic circulation of bile acids is related to normal inter-digestive gastrointestinal motility, with the gut peptide motilin also being involved. This study aimed to investigate the effect of intraduodenal artificial bile infusion on antroduodenal and gallbladder motility so as to further elucidate the controlling factors. Methods: Twelve fasting, healthy male volunteers received artificial bile (80 mol% bile acids; 15 mol% phospholipids; 5 mol% cholesterol) or placebo (saline) intraduodenally for 10 min starting 30 min after the end of phase III, according to a double-blind, randomised, cross-over design. Antroduodenal motility, gallbladder volumes, and plasma motilin levels were measured. All values are means ± SEM. Results: The interval between infusion and the subsequent phase III, as well as the origin of this phase III were not significantly different between bile and saline. Antral pressure waves were significantly more frequent during and immediately after bile infusion compared with saline infusion (p < 0.05). The duration of phase I following infusion was significantly longer after bile (24.8 ± 3.7 min) than after saline infusion (13.1 ± 1.7 min; p < 0.05). The mean gallbladder volume tended to increase in the hours following bile infusion, but to decrease after saline infusion (p = 0.06). Plasma motilin increased after bile and saline infusion in an almost identical way. Conclusion: This study provides no clear evidence for a role of intraduodenal artificial bile (i.e. its main constituents) in the regulation of migrating motor complex cycling or feedback inhibition of inter-digestive gallbladder emptying.

Effects of ileal bile salts on fasting small intestinal and gallbladder motility

“…13,15 In humans, two previous studies from our group found no effects of intraduodenal bile salt infusions on timing of the various phases of the MMC. 4,5 In contrast, in the present study, ileal infusion of the same mixed micelles led to an earlier appearance of phase III activity. One may hypothesize that ileal rather than duodenal bile salts affect cholinergic influences on small intestinal motility.…”

“…After biliary diversion in dogs, some investigators have reported unchanged MMC cycling, 14 whereas others reported a loss of MMCs 13,15 . In humans, two previous studies from our group found no effects of intraduodenal bile salt infusions on timing of the various phases of the MMC 4,5 . In contrast, in the present study, ileal infusion of the same mixed micelles led to an earlier appearance of phase III activity.…”

“…Although the physiological importance of intestinal bile salts in the interdigestive state is largely unknown, it is conceivable that bile salts play a role in the prevention of bacterial overgrowth by their antibacterial activity 3 and interplay with fasting small intestinal motility (especially phase III activity). A recent study from our group showed no effects of duodenal bile salt infusions on small bowel motility under normal conditions 4 . Furthermore, although after intraduodenal bile salt depletion by cholestyramine a local increase in motor activity occurred after duodenal infusion of mixed bile salt micelles, there were no effects on timing of the various phases of the MMC 5 .…”

“…A recent study from our group showed no effects of duodenal bile salt infusions on small bowel motility under normal conditions. 4 Furthermore, although after intraduodenal bile salt depletion by cholestyramine a local increase in motor activity occurred after duodenal infusion of mixed bile salt micelles, there were no effects on timing of the various phases of the MMC. 5 Nevertheless, intraduodenal bile salt depletion by cholestyamine induced strong gallbladder contraction, whereas intraduodenal bile salt infusion increased gallbladder volumes, suggesting the existence of a negative feedback mechanism by intraduodenal bile salts on gallbladder motility in the fasting state.…”

Effects of motilin on human interdigestive gastrointestinal and gallbladder motility, and involvement of 5HT3 receptors

“…Our study resembled this association in time, as motilin‐induced gallbladder emptying preceded antral phase III. Based on previous findings with intraduodenal bile infusion, 37 we believe that the appearance of phase III following motilin infusion is the effect of motilin per se , rather than a direct effect of gallbladder excretion into the duodenum. Following motilin‐induced gallbladder emptying, the gallbladder refilled during and immediately after duodenal passage of the motilin‐induced phase III, as has been suggested previously for spontaneous phases III 10 .…”