Background & Aims: Circulating levels of ghrelin, a stomach peptide that promotes food intake, rise before and fall after meal. We aimed to investigate whether there is an independent contribution of the small bowel to the regulation of ghrelin and appetite.

Methods: A duodenal-jejunal bypass (DJB) with preservation of normal gastric volume and exposure to nutrients was performed in 12-week-old obese Zucker ZDF fa/fa rat. Food intake, weight gain, 48-hour fasting and 24-hour re-feeding levels of total and acylated ghrelin were measured. The DJB was challenged against gastric restriction (GB), Diet and a sham operation in matched animals. Normal controls were age-matched Wistar rats, which underwent either DJB or a sham operation.

Results: The Zucker obese animals showed a paradoxical increase of acylated ghrelin levels after re-feeding (+30% with respect to fasting levels; P = 0.001), an abnormality that was completely reversed only by the DJB (-30%; P = 0.01) but not after GB, Diet or sham operation. In obese rats the DJB resulted in significantly less food intake and weight gain compared with both GB (P < 0.05) and sham operation (P < 0.01). In sharp contrast, the DJB did not alter food intake and weight gain in normal rats.

Conclusion: The DJB does not physically restrict the flow of food but restores meal-induced suppression of acylated ghrelin and significantly reduce food intake in Zucker obese rats. These findings suggest an independent intestinal contribution to the regulation of the dynamic ghrelin response to eating and the possibility that a defective signaling from the proximal bowel be involved in the pathogenesis of obesity/hyperphagia.