7α-脱羟基化细菌可增加胆结石患者胆汁中脱氧胆酸的输入及胆固醇饱和度。

7 alpha-dehydroxylating bacteria enhance deoxycholic acid input and cholesterol saturation of bile in patients with gallstones.

作者信息

Berr F, Kullak-Ublick G A, Paumgartner G, Münzing W, Hylemon P B

机构信息

Department of Medicine II, University of Munich, Germany.

出版信息

Gastroenterology. 1996 Dec;111(6):1611-20. doi: 10.1016/s0016-5085(96)70024-0.

DOI:10.1016/s0016-5085(96)70024-0

PMID:8942741

Abstract

BACKGROUND & AIMS: Excessive deoxycholic acid (DCA) in the bile acid pool with cholesterol supersaturation of bile is prevalent in patients with cholesterol gallstones (CGs). This study examined whether this is caused by enhanced conversion of cholic acid (CA) to DCA by intestinal bacteria.

METHODS

Ten patients with CGs with DCA excess (DCA/CA pool ratio, > 1.5) and 10 patients with low DCA (ratio, < 1.0) were compared for CA and DCA kinetics, ileal absorption of 75-Se-homotaurocholic acid (75-SeHCAT), and CA-7 alpha-dehydroxylation activity of the fecal microflora; the effects of ampicillin treatment on DCA excess were studied in 7 patients.

RESULTS

Patients with DCA excess and low DCA differed (P < 0.01) in the pool size of CA (mean, 5.8 vs. 34) and DCA (28 vs. 11 mumol/kg) and DCA input (8.8 vs. 3.5 mumol.kg-1.day-1. Whereas 75-SeHCAT excretion was similar, CA-7 alpha-dehydroxylation activity and levels of fecal 7 alpha-dehydroxylation bacteria were 3-fold and 1000-fold higher (P < 0.01) in patients with DCA excess, respectively. Ampicillin treatment decreased (P < 0.02) CA-7 alpha-dehydroxylation activity and DCA pool size, expanded the CA pool to normal size, and lowered cholesterol saturation of bile.

CONCLUSIONS

Increased CA-7 alpha-dehydroxylation activity of the intestinal microflora may be an important factor for CG formation or growth in these patients.

摘要

背景与目的

在胆固醇性胆结石（CG）患者中，胆汁酸池中的脱氧胆酸（DCA）过量且胆汁胆固醇过饱和的情况很常见。本研究旨在探讨这是否是由于肠道细菌将胆酸（CA）转化为DCA的能力增强所致。

方法

比较了10例DCA过量（DCA/CA池比值>1.5）的CG患者和10例DCA水平较低（比值<1.0）的患者的CA和DCA动力学、75-硒-同型牛磺胆酸（75-SeHCAT）的回肠吸收情况以及粪便微生物群的CA-7α-脱羟基化活性；研究了7例患者接受氨苄西林治疗对DCA过量的影响。

结果

DCA过量和DCA水平较低的患者在CA池大小（平均值分别为5.8和34）、DCA池大小（28和11μmol/kg）和DCA输入量（8.8和3.5μmol·kg-1·天-1）方面存在差异（P<0.01）。虽然75-SeHCAT排泄情况相似，但DCA过量患者的CA-7α-脱羟基化活性和粪便7α-脱羟基化细菌水平分别高出3倍和1000倍（P<0.01）。氨苄西林治疗降低了（P<0.02）CA-7α-脱羟基化活性和DCA池大小，使CA池扩大至正常大小，并降低了胆汁胆固醇饱和度。