The human intestinal tract is densely colonized by a microbial community that is subject to intense competition. Bacteria in this complex habitat seek to outcompete their neighbors for nutrients and eliminate competitors with antibacterial toxins. Antagonism can be mediated by diverse effectors including toxic proteins and small molecule inhibitors that are released extracellularly or delivered by specialized secretion systems to targeted cells. Two prototypical microbiota-derived enterotoxins, colibactin and tilimycin, and the newly discovered family of indolimines represent an expanding group of non-proteinaceous small molecules which specifically target DNA. In addition to cell killing, they generate mutations and genome instability in intoxicated microbes and host cells alike. They have been studied in detail because of their direct toxicity to human cells and important etiological roles in intestinal pathologies. Increasing evidence, however, reveals that these commensal genotoxins are also mediators of interbacterial antagonism, which impacts gut microbial ecology. In this review, we illustrate the functional versatility of commensal genotoxins in the gut ecosystem.

中文翻译：

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微生物群衍生的小分子基因毒素：肠道生态系统中的宿主相互作用和生态影响。


人类肠道被微生物群落密集定植，该微生物群落受到激烈竞争的影响。在这个复杂的栖息地中，细菌试图在营养物质方面超越邻居，并通过抗菌毒素消灭竞争对手。拮抗作用可由多种效应子介导，包括毒性蛋白和小分子抑制剂，这些效应物在细胞外释放或由专门的分泌系统递送到目标细胞。两种原型微生物群衍生的肠毒素 colibactin 和 tilimycin 以及新发现的吲哚胺家族代表了一组不断扩大的非蛋白小分子，它们专门靶向 DNA。除了细胞杀伤外，它们还会在中毒的微生物和宿主细胞中产生突变和基因组不稳定性。由于它们对人体细胞具有直接毒性，并且在肠道病理学中具有重要的病因学作用，因此对它们进行了详细研究。然而，越来越多的证据表明，这些共生基因毒素也是细菌间拮抗作用的介质，这会影响肠道微生物生态学。在这篇综述中，我们说明了共生基因毒素在肠道生态系统中的功能多功能性。