Bilirubin is a component of the heme catabolic pathway that is essential for liver function and has been shown to reduce hepatic fat accumulation. High plasma bilirubin levels are reflective of liver disease due to an injurious effect on hepatocytes. In healthy liver, bilirubin is conjugated and excreted to the intestine and converted by microbes to urobilinoids, which are reduced to the predominant pigment in feces, stercobilin, or reabsorbed. The function of urobilinoids in the gut or their physiological relevance of reabsorption is not well understood. In this review, we discuss the relationship of hepatic bilirubin signaling to the intestinal microbiota and its regulation of the liver-gut axis, as well as its capacity to mediate these processes.

中文翻译：

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肝-肠信号轴中的胆红素

胆红素是血红素分解代谢途径的一个组成部分，对肝功能至关重要，已被证明可以减少肝脏脂肪堆积。由于对肝细胞的损害作用，高血浆胆红素水平反映了肝脏疾病。在健康的肝脏中，胆红素结合并排泄到肠道，并被微生物转化为尿胆素，后者被还原为粪便中的主要色素、粪胆素或被重吸收。尿胆素在肠道中的功能或其重吸收的生理相关性尚不清楚。在这篇综述中，我们讨论了肝胆红素信号与肠道微生物群的关系及其对肝肠轴的调节，以及其介导这些过程的能力。