粪胆汁酸与大肠癌关系的研究

A Study of the Relationship Between Fecal Bile Acids and Colorectal Cancer

作者以气相色谱法分别测定正常人高、低脂饮食、大肠癌和大肠息肉患者及结直肠次全切除者的类胆汁酸成份和浓度。结果显示,高动物脂肪、高植物脂肪和高混合脂肪饮食者石胆酸(LCA)和脱氧胆酸(DCA)浓度显著高于低脂饮食;大肠癌患者LCA和DCA浓度显著高于对照组,大肠息肉患者DCA浓度亦显著高于对照组;结直肠次全切除者鹅脱氧胆酸(CDCA)浓度显著高于对照组。结果提示,高脂饮食增加次级胆汁酸浓度(被认为是大肠癌的辅致物或促癌物),我国大肠癌发病率不断增高可能与粪胆汁酸代谢改变有关,结直肠次全切除者CDCA浓度显著增高有益于防止剩余结直肠段内息肉的再生或癌变,减少脂肪摄入量可能减少大肠癌的发病率。

The fecal bile acid composition and concentration in different groups of people (including 10 healthy subjects on high and low fat diets, 26 colonic or rectal cancer patients, 10 colorectal polyp patients, 10 subtotal proctocolectomy patients and 21 controls)were measured by gas chromatograhpy, We found: (1) the concentration of lithocholic acid (LCA) and deoxycholic acid (DCA) in three groups on high fat diet was significantly higher than in low fat diet group (P<0.05～0.01). (2) the concentration of LCA and DCA in colorectal cancer group was significantly higher than that in controls (P<0.05～0.01). The concentration of DCA in colorectal polyp group was also significantly higher than in controlos (P<0.01). (3) the concentration of chenodeoxycholic acid (CDCA) in patients after subtotal proctocolectomy was significantly higher than that in controls (P<0.01). This investigation reveals: (1) high fat diets can increase the concentration of secondary bile acids which is believed to be the promotor of colorectal cancer. (2) the increasing incidence of colorectal cancer in China may be closely related to a change of fecal bile acid metabolism. (3) the significant rise in the concentration of CDCA in subtotal proctocolectomy patients will be beneficial in preventing polyp regeneration or malignant change. (4) a reduced amont of dietary fat intake may be beneficial in reducing the incidence of colorectal cancer in certain groups of people.