Van Eldere J, Robben J, Caenepeel P, Eyssen H
Rega Institute, Catholic University of Leuven, Belgium.
J Steroid Biochem. 1988 Jan;29(1):33-9. doi: 10.1016/0022-4731(88)90373-1.
From mouse fecal material we have isolated four strictly anaerobic bacteria which, when associated with germfree mice or rats, reduced the cecal volume by 80 and 60%, respectively. This cecal volume-reducing flora did not metabolize estrone-3-sulfate, taurolithocholate-3-sulfate or taurolithocholate but gnotobiotic rats associated with this particular flora (CRF-rats) excreted these compounds faster in feces plus urine than did germfree rats. The time needed for 50% excretion (t1/2) of orally administered estrone-3-sulfate was 32 h in germfree rats versus 13 h in CRF rats; for intraperitoneally injected taurolithocholate-3-sulfate the t1/2 was 63 h in germfree versus 17 h in CRF rats and for taurolithocholate the t1/2 was 199 h in germfree and 96 h in CRF rats. Association of germfree rats with the cecal volume-reducing flora did not change the cecal absorption rate of estrone-3-sulfate, but shortened the 50% small intestinal transit time of [14C]PEG from 10 to 3 h; a value also found in conventional rats. These results stress the important influence of the intestinal microflora on the absorption and excretion of steroids via its effect on the physiology of the whole intestinal tract and point to the deficiencies inherent to the use of germfree animals in excretion studies.
我们从小鼠粪便中分离出了四种严格厌氧的细菌，当将它们与无菌小鼠或大鼠关在一起时，分别使盲肠体积减少了80%和60%。这种使盲肠体积减小的菌群不能代谢硫酸雌酮、硫酸牛磺石胆酸或牛磺石胆酸，但与这种特定菌群关在一起的悉生大鼠（CRF大鼠）比无菌大鼠能更快地通过粪便和尿液排出这些化合物。口服硫酸雌酮50%排出所需时间（t1/2）在无菌大鼠中为32小时，而在CRF大鼠中为13小时；对于腹腔注射的硫酸牛磺石胆酸，t1/2在无菌大鼠中为63小时，在CRF大鼠中为17小时；对于牛磺石胆酸，t1/2在无菌大鼠中为199小时，在CRF大鼠中为96小时。无菌大鼠与使盲肠体积减小的菌群关在一起并没有改变硫酸雌酮的盲肠吸收率，但将[14C]聚乙二醇的50%小肠转运时间从10小时缩短至3小时；这一数值在普通大鼠中也能找到。这些结果强调了肠道微生物群通过对整个肠道生理的影响，对类固醇吸收和排泄的重要影响，并指出了在排泄研究中使用无菌动物所固有的缺陷。
