Bile acids are signalling hormones involved in the regulation of several metabolic pathways. The ability of bile acids to bind and signal through their receptors is modulated by the gut microbiome, since the microbiome contributes to the regulation and synthesis of bile acids as well to their physiochemical properties. From the gut, bacteria have been shown to send signals to the central nervous system via their metabolites, thus affecting the behaviour and brain function of the host organism. In the last years it has become increasingly evident that bile acids affect brain function, during normal physiological and pathological conditions. Although bile acids may be synthesized locally in the brain, the majority of brain bile acids are taken up from the systemic circulation. Since the composition of the brain bile acid pool may be regulated by the action of intestinal bacteria, it is possible that bile acids function as a communication bridge between the gut microbiome and the brain. However, little is known about the molecular mechanisms and the physiological roles of bile acids in the central nervous system. The possibility that bile acids may be a direct link between the intestinal microbiome and the brain is also an understudied subject. Here we review the influence of gut bacteria on the bile acid pool composition and properties, as well as striking evidence showing the role of bile acids as neuroactive molecules.

胆汁酸是信号激素，参与多种代谢途径的调节。胆汁酸通过其受体结合和发出信号的能力受肠道微生物群的调节，因为微生物群有助于胆汁酸的调节和合成以及它们的理化特性。从肠道中，细菌已被证明可以通过其代谢物向中枢神经系统发送信号，从而影响宿主生物的行为和大脑功能。在过去的几年里，胆汁酸在正常生理和病理条件下影响大脑功能的情况越来越明显。虽然胆汁酸可以在大脑局部合成，但大部分脑胆汁酸是从体循环中摄取的。由于大脑胆汁酸池的组成可能受肠道细菌的作用调节，胆汁酸可能充当肠道微生物组和大脑之间的沟通桥梁。然而，关于胆汁酸在中枢神经系统中的分子机制和生理作用知之甚少。胆汁酸可能是肠道微生物组和大脑之间的直接联系的可能性也是一个研究不足的主题。在这里，我们回顾了肠道细菌对胆汁酸池组成和特性的影响，以及显示胆汁酸作为神经活性分子的作用的惊人证据。关于胆汁酸在中枢神经系统中的分子机制和生理作用知之甚少。胆汁酸可能是肠道微生物组和大脑之间的直接联系的可能性也是一个研究不足的主题。在这里，我们回顾了肠道细菌对胆汁酸池组成和特性的影响，以及显示胆汁酸作为神经活性分子的作用的惊人证据。关于胆汁酸在中枢神经系统中的分子机制和生理作用知之甚少。胆汁酸可能是肠道微生物组和大脑之间的直接联系的可能性也是一个研究不足的主题。在这里，我们回顾了肠道细菌对胆汁酸池组成和特性的影响，以及显示胆汁酸作为神经活性分子的作用的惊人证据。