A general consensus exists that IBD is associated with compositional and metabolic changes in the intestinal microbiota (dysbiosis). However, a direct causal relationship between dysbiosis and IBD has not been definitively established in humans. Findings from animal models have revealed diverse and context-specific roles of the gut microbiota in health and disease, ranging from protective to pro-inflammatory actions. Moreover, evidence from these experimental models suggest that although gut bacteria often drive immune activation, chronic inflammation in turn shapes the gut microbiota and contributes to dysbiosis. The purpose of this Review is to summarize current associations between IBD and dysbiosis, describe the role of the gut microbiota in the context of specific animal models of colitis, and discuss the potential role of microbiota-focused interventions in the treatment of human IBD. Ultimately, more studies will be needed to define host–microbial relationships relevant to human disease and amenable to therapeutic interventions.

人们普遍认为 IBD 与肠道微生物群的组成和代谢变化（菌群失调）有关。然而，人类肠道菌群失调与 IBD 之间的直接因果关系尚未明确。动物模型的研究结果揭示了肠道微生物群在健康和疾病中的多种且特定于环境的作用，从保护作用到促炎作用。此外，来自这些实验模型的证据表明，尽管肠道细菌通常会驱动免疫激活，但慢性炎症反过来会塑造肠道微生物群并导致菌群失调。本综述的目的是总结当前 IBD 与生态失调之间的关联，描述肠道微生物群在特定结肠炎动物模型中的作用，并讨论以微生物群为重点的干预措施在人类 IBD 治疗中的潜在作用。最终，需要更多的研究来定义与人类疾病相关并适合治疗干预的宿主-微生物关系。