The gut microbiome has emerged as a key regulator of host metabolism. Here we review the various mechanisms through which the gut microbiome influences the energy metabolism of its host, highlighting the complex interactions between gut microbes, their metabolites and host cells. Among the most important bacterial metabolites are short-chain fatty acids, which serve as a direct energy source for host cells, stimulate the production of gut hormones and act in the brain to regulate food intake. Other microbial metabolites affect systemic energy expenditure by influencing thermogenesis and adipose tissue browning. Both direct and indirect mechanisms of action are known for specific metabolites, such as bile acids, branched chain amino acids, indole propionic acid and endocannabinoids. We also discuss the roles of specific bacteria in the production of specific metabolites and explore how external factors, such as antibiotics and exercise, affect the microbiome and thereby energy homeostasis. Collectively, we present a large body of evidence supporting the concept that gut microbiota-based therapies can be used to modulate host metabolism, and we expect to see such approaches moving from bench to bedside in the near future.

肠道微生物组已成为宿主代谢的关键调节剂。在这里，我们回顾了肠道微生物组通过各种机制影响其宿主的能量代谢，突出了肠道微生物，它们的代谢产物和宿主细胞之间的复杂相互作用。短链脂肪酸是最重要的细菌代谢物，短链脂肪酸可作为宿主细胞的直接能量来源，刺激肠道激素的产生并在大脑中调节食物的摄入。其他微生物代谢产物通过影响生热和脂肪组织褐变而影响全身能量消耗。对于特定的代谢产物，例如胆汁酸，支链氨基酸，吲哚丙酸和内源大麻素，直接和间接的作用机理都是已知的。我们还将讨论特定细菌在特定代谢产物产生中的作用，并探讨诸如抗生素和运动等外部因素如何影响微生物组，从而影响能量稳态。总的来说，我们提供了大量证据支持基于肠道菌群的疗法可用于调节宿主新陈代谢的概念，并且我们希望在不久的将来看到这种方法从实验台转移到床旁。