Kennedy M J, Rogers A L, Yancey R J
Department of Botany and Plant Pathology, Michigan State University, East Lansing 48824.
Mycopathologia. 1988 Sep;103(3):125-34. doi: 10.1007/BF00436810.
The finding by earlier workers that Escherichia coli suppressed the growth of Candida albicans in vitro or in gnotobiotic mice has led to numerous, erroneous conclusions regarding the identity of the organisms and mechanisms responsible for the suppression of Candida in the gut. This is due, in part, to the fact that nearly all studies to date have not reflected interactions as they occur in the intestinal tract. This paper describes a series of experiments that establish that an anaerobic continuous-flow (CF) culture model of the ecology of the large intestinal flora reproduces interactions between bacteria and Candida as they occur in the large intestine. This was determined in the following ways. (i) Bacterial counts in CF cultures of conventional mouse cecal flora or human fecal flora closely resembled that found in the mouse intestine and human feces. (ii) Dense layers of bacterial growth that formed on the glass walls of the CF culture vessels resembled bacterial populations that colonize intestinal mucosa. (iii) Total and individual levels of certain metabolic end-products of the predominant anaerobic bacterial flora present in CF cultures coincided with those found in the large intestine of conventional mice or human feces used to establish the CF cultures. (iv) C. albicans was eliminated from CF cultures of mouse cecal flora at a rate similar to that of untreated experimental animals. (v) Contents of CF cultures fed to antibiotic-treated mice redressed several cecal abnormalities, and suppressed Candida populations to levels found in conventional animals. Thus, a number of complex ecological mechanisms were maintained in CF cultures which normally control Candida populations in the large intestine. It is suggested, therefore, that the CF culture model should help to further define the mechanisms which control C. albicans and other fungi in the intestinal tract, as well as define which components of the indigenous microflora are responsible for suppression of Candida in the gut.
早期研究人员发现大肠杆菌在体外或无菌小鼠体内可抑制白色念珠菌的生长，这导致了关于肠道中抑制念珠菌的微生物种类及其作用机制的众多错误结论。部分原因在于，迄今为止几乎所有的研究都未能反映肠道内实际发生的相互作用。本文描述了一系列实验，这些实验证实，大肠菌群生态学的厌氧连续流动（CF）培养模型能够重现大肠内细菌与念珠菌之间实际发生的相互作用。这是通过以下方式确定的。（i）常规小鼠盲肠菌群或人类粪便菌群的CF培养物中的细菌计数与在小鼠肠道和人类粪便中发现的计数非常相似。（ii）在CF培养容器玻璃壁上形成的密集细菌生长层类似于定殖在肠黏膜上的细菌群体。（iii）CF培养物中主要厌氧菌群的某些代谢终产物的总量和个体水平与用于建立CF培养物的常规小鼠大肠或人类粪便中的水平一致。（iv）白色念珠菌在小鼠盲肠菌群的CF培养物中的清除速率与未处理的实验动物相似。（v）将CF培养物的内容物喂给经抗生素处理的小鼠，可纠正几种盲肠异常情况，并将念珠菌数量抑制到常规动物中的水平。因此，CF培养物中维持了许多通常控制大肠中念珠菌数量的复杂生态机制。因此，有人认为CF培养模型应有助于进一步确定控制肠道中白色念珠菌和其他真菌的机制，以及确定本土微生物群中哪些成分负责抑制肠道中的念珠菌。
