The trillions of bacteria that constitutively colonize the human gut collectively generate thousands of unique small molecules. These microbial metabolites can accumulate both locally and systemically and potentially influence nearly all aspects of mammalian biology, including immunity, metabolism, and even mood and behavior. In this review, we briefly summarize recent work identifying bioactive microbiota metabolites, the means through which they are synthesized, and their effects on host physiology. Rather than offering an exhaustive list of all known bioactive microbial small molecules, we select a few examples from each key class of metabolites to illustrate the diverse impacts of microbiota-derived compounds on the host. In addition, we attempt to address the microbial logic behind specific biotransformations. Finally, we outline current and emerging strategies for identifying previously undiscovered bioactive microbiota metabolites that may shape human health and disease.

人类肠道内的数万亿细菌共同产生数以千计的独特小分子。这些微生物代谢物可以在局部和全身积累，并可能影响哺乳动物生物学的几乎所有方面，包括免疫、新陈代谢，甚至情绪和行为。在这篇综述中，我们简要总结了最近的工作，以确定生物活性微生物代谢物、它们的合成方式以及它们对宿主生理学的影响。我们没有提供所有已知生物活性微生物小分子的详尽列表，而是从每个关键代谢物类别中选择了一些例子来说明微生物群衍生化合物对宿主的不同影响。此外，我们尝试解决特定生物转化背后的微生物逻辑。最后，我们概述了当前和新兴的策略，用于识别以前未发现的可能影响人类健康和疾病的生物活性微生物代谢物。