Department of General Surgery, King's College Hospital, Denmark Hill, London, UK, SE5 9RS,
Obes Surg. 2014 May;24(5):796-805. doi: 10.1007/s11695-013-1166-x.
Bariatric surgical procedures are classified by their presumed mechanisms of action: restrictive, malabsorptive or a combination of both. However, this dogma is questionable and remains unproven. We investigated post-operative changes in nutrient absorption and transit time following bariatric surgery.
Participants were recruited into four groups: obese controls (body mass index (BMI) >30 kg/m2, n = 7), adjustable gastric banding (n = 6), Roux-en-Y gastric bypass (RYGB, n = 7) and biliopancreatic diversion with duodenal switch (DS, n = 5). Participants underwent sulphasalazine/sulphapyridine tests (oro-caecal transit time); fasting plasma citrulline (functional enterocyte mass); 3 days faecal collection for faecal elastase 1 (FE-1); calprotectin (FCp); faecal fatty acids (pancreatic exocrine function, gut inflammation and fat excretion, respectively); and 5 h D-xylose, L-rhamnose and lactulose test (intestinal absorption and permeability).
Age and gender were not different but BMI differed between groups (p = 0.001). No difference in oro-caecal transit time (p = 0.935) or functional enterocyte mass (p = 0.819) was detected. FCp was elevated post-RYGB vs. obese (p = 0.016) and FE-1 was reduced post-RYGB vs. obese (p = 0.002). Faecal fat concentrations were increased post-DS vs. obese (p = 0.038) and RYGB (p = 0.024) and were also higher post-RYGB vs. obese (p = 0.033). Urinary excretion of D-xylose and L-rhamnose was not different between the groups; however, lactulose/rhamnose ratio was elevated post-DS vs. other groups (all p < 0.02), suggesting increased intestinal permeability.
Following RYGB, there are surprisingly few abnormalities or indications of severe malabsorption of fats or sugars. Small bowel adaptation after bariatric surgery may be key to understanding the mechanisms responsible for the beneficial metabolic effects of these operations.
减重手术的分类依据是其假定的作用机制：限制型、吸收不良型或两者结合。然而，这种教条主义是有问题的，尚未得到证实。我们研究了减重手术后营养吸收和转运时间的变化。
将参与者分为四组：肥胖对照组（BMI>30kg/m2，n=7）、可调胃带（n=6）、Roux-en-Y 胃旁路术（RYGB，n=7）和胆胰分流十二指肠转位术（DS，n=5）。参与者接受柳氮磺胺吡啶/磺胺吡啶试验（口-盲肠转运时间）；空腹血浆瓜氨酸（功能性肠细胞质量）；3 天粪便收集用于粪便弹性蛋白酶 1（FE-1）；钙卫蛋白（FCp）；粪便脂肪酸（胰腺外分泌功能、肠道炎症和脂肪排泄）；以及 5 小时 D-木糖、L-鼠李糖和乳果糖试验（肠道吸收和通透性）。
年龄和性别无差异，但 BMI 各组间有差异（p=0.001）。口-盲肠转运时间（p=0.935）或功能性肠细胞质量（p=0.819）无差异。RYGB 术后 FCp 高于肥胖组（p=0.016），RYGB 术后 FE-1 低于肥胖组（p=0.002）。DS 术后粪便脂肪浓度高于肥胖组（p=0.038）和 RYGB 组（p=0.024），RYGB 术后粪便脂肪浓度也高于肥胖组（p=0.033）。各组间尿 D-木糖和 L-鼠李糖排泄无差异；然而，DS 术后乳果糖/鼠李糖比值高于其他组（p<0.02），提示肠道通透性增加。
RYGB 术后，脂肪或糖吸收不良的异常或迹象很少。减重手术后小肠的适应性可能是理解这些手术有益代谢作用的关键机制。
