Dept. of Investigative Medicine, Hammersmith Hospital, Imperial College London, Du Cane Road, London W12 0NN, UK.
Am J Physiol Regul Integr Comp Physiol. 2011 Oct;301(4):R1057-66. doi: 10.1152/ajpregu.00139.2011. Epub 2011 Jul 6.
Roux-en-Y gastric bypass is the most effective therapy for morbid obesity. This study investigated how gastric bypass affects intake of and preference for high-fat food in an experimental (rat) study and within a trial setting (human). Proportion of dietary fat in gastric bypass patients was significantly lower 6 yr after surgery compared with patients after vertical-banded gastroplasty (P = 0.046). Gastric bypass reduced total fat and caloric intake (P < 0.001) and increased standard low-fat chow consumption compared with sham controls (P < 0.001) in rats. Compared with sham-operated rats, gastric bypass rats displayed much lower preferences for Intralipid concentrations > 0.5% in an ascending concentration series (0.005%, 0.01%, 0.05%, 0.1%, 0.5%, 1%, 5%) of two-bottle preference tests (P = 0.005). This effect was demonstrated 10 and 200 days after surgery. However, there was no difference in appetitive or consummatory behavior in the brief access test between the two groups (P = 0.71) using similar Intralipid concentrations (0.005% through 5%). Levels of glucagon-like peptide-1 (GLP-1) were increased after gastric bypass as expected. An oral gavage of 1 ml corn oil after saccharin ingestion in gastric bypass rats induced a conditioned taste aversion. These findings suggest that changes in fat preference may contribute to long-term maintained weight loss after gastric bypass. Postingestive effects of high-fat nutrients resulting in conditioned taste aversion may partially explain this observation; the role of GLP-1 in mediating postprandial responses after gastric bypass requires further investigation.
胃旁路术是治疗病态肥胖最有效的方法。本研究通过实验（大鼠）研究和临床试验（人类）调查了胃旁路术如何影响高脂肪食物的摄入和偏好。与垂直带胃成形术（vertical-banded gastroplasty）患者相比，胃旁路术后 6 年的膳食脂肪比例显著降低（P = 0.046）。胃旁路术降低了大鼠的总脂肪和热量摄入（P < 0.001），并增加了标准低脂饲料的摄入量（与假手术对照组相比，P < 0.001）。与假手术大鼠相比，胃旁路大鼠在双瓶偏好测试（two-bottle preference test）的递增浓度系列（0.005%、0.01%、0.05%、0.1%、0.5%、1%、5%）中对 Intralipid 浓度>0.5%的偏好明显降低（P = 0.005）。在手术后 10 天和 200 天均观察到这种效果。然而，在两组之间，使用类似的 Intralipid 浓度（0.005%至 5%），在短暂访问测试（brief access test）中，食欲或饱食行为没有差异（P = 0.71）。胃旁路术后，胰高血糖素样肽-1（glucagon-like peptide-1，GLP-1）水平升高是预期的。胃旁路大鼠在摄入糖精后口服 1 毫升玉米油会引起条件性味觉厌恶。这些发现表明，脂肪偏好的改变可能有助于胃旁路术后长期维持体重减轻。高脂肪营养素的餐后作用导致条件性味觉厌恶，可能部分解释了这一观察结果；GLP-1 在介导胃旁路术后餐后反应中的作用需要进一步研究。
