We tested two hypotheses concerning the dynamics of intestinal microbial communities of young mice following antibiotic-induced disturbance. The first is that disturbance of the bacterial community causes disturbance of the fungal community. Our results were consistent with that hypothesis. Antibiotics significantly altered bacterial community structure. Antibiotics also altered fungal community structure, significantly increasing the relative abundance of Candida lusitaniae, a known pathogen, while simultaneously significantly decreasing the relative abundances of several other common fungal species. The result was a temporary decrease in fungal diversity. Moreover, bacterial load was negatively correlated with the relative abundances of Candida lusitaniae and Candida parapsilosis, while it was positively correlated with the relative abundances of many other fungal species. Our second hypothesis is that control mice serve as a source of probiotics capable of invading intestines of mice with disturbed microbial communities and restoring pre-antibiotic bacterial and fungal communities. However, we found that control mice did not restore disturbed microbial communities. Instead, mice with disturbed microbial communities induced disturbance in control mice, consistent with the hypothesis that antibiotic-induced disturbance represents an alternate stable state that is easier to achieve than to correct. Our results indicate the occurrence of significant interactions among intestinal bacteria and fungi and suggest that the stimulation of certain bacterial groups may potentially be useful in countering the dominance of fungal pathogens such as Candida spp. However, the stability of disturbed microbial communities could complicate recovery.

我们测试了两种有关抗生素诱导的干扰后年轻小鼠肠道微生物群落动态的假说。首先是细菌群落的干扰导致真菌群落的干扰。我们的结果与该假设一致。抗生素会显着改变细菌群落结构。抗生素还改变了真菌的群落结构，显着增加了已知病原体假丝酵母念珠菌的相对丰度，同时显着降低了其他几种常见真菌物种的相对丰度。结果是真菌多样性暂时降低。此外，细菌载量与黄念珠菌的相对丰度呈负相关。和副念珠菌，但与许多其他真菌物种的相对丰度呈正相关。我们的第二个假设是，对照小鼠可作为益生菌的来源，能够侵入微生物群落受损的小鼠的肠道，并恢复抗生素前细菌和真菌的群落。但是，我们发现对照小鼠不能恢复受干扰的微生物群落。取而代之的是，微生物群落受到干扰的小鼠在对照小鼠中引起了干扰，这与以下假设有关：抗生素引起的干扰代表了另一种稳定状态，这种状态容易实现而不是纠正。念珠菌属 但是，受干扰的微生物群落的稳定性会使恢复工作复杂化。