Cancer cachexia is a metabolic syndrome characterized by unintended weight loss and muscle wasting. It has a strong negative impact on survival. Its underlying mechanisms involve systemic inflammation and insulin resistance, which are known to be influenced by the gut microbiota. Preclinical studies support a role for the gut microbiota in cancer cachexia by demonstrating that cachectic mice display: 1) various gut microbiota composition changes; 2) increased gut permeability and translocation of pro-inflammatory microbial compounds; 3) muscle atrophy-related processes linked to gut microbiota properties; 4) positive effects of microbiota-modulating interventions. Data on the relationships between gut microbiota, insulin resistance, and hepatic/adipose tissue metabolism in cachexia models are lacking. Nevertheless, the available data and existing evidence for the impact of gut microbiota on metabolic aberrations in human obesity urge for exploration of its role in human cancer cachexia. We provide practical recommendations and discuss the challenges for such future clinical studies.

癌症恶病质是一种代谢综合征，其特征是意外体重减轻和肌肉萎缩。它对生存有很大的负面影响。其潜在机制涉及全身性炎症和胰岛素抵抗，已知它们受肠道微生物群的影响。临床前研究通过证明恶病质小鼠表现出以下特征，支持肠道微生物群在癌症恶病质中的作用：1）各种肠道微生物群组成的变化；2) 增加肠道通透性和促炎微生物化合物的易位；3) 与肠道微生物群特性相关的肌肉萎缩相关过程；4) 微生物群调节干预措施的积极作用。缺乏关于恶病质模型中肠道微生物群、胰岛素抵抗和肝/脂肪组织代谢之间关系的数据。尽管如此，关于肠道微生物群对人类肥胖代谢异常影响的现有数据和现有证据迫切需要探索其在人类癌症恶病质中的作用。我们提供实用建议并讨论此类未来临床研究的挑战。