Drugs and Bugs: The Gut-Brain Axis and Substance Use Disorders.

Substance use disorders (SUDs) represent a significant public health crisis. Worldwide, 5.4% of the global disease burden is attributed to SUDs and alcohol use, and many more use psychoactive substances recreationally. Often associated with comorbidities, SUDs result in changes to both brain function and physiological responses. Mounting evidence calls for a precision approach for the treatment and diagnosis of SUDs, and the gut microbiome is emerging as a contributor to such disorders. Over the last few centuries, modern lifestyles, diets, and medical care have altered the health of the microbes that live in and on our bodies; as we develop, our diets and lifestyle dictate which microbes flourish and which microbes vanish. An increase in antibiotic treatments, with many antibiotic interventions occurring early in life during the microbiome's normal development, transforms developing microbial communities. Links have been made between the microbiome and SUDs, and the microbiome and conditions that are often comorbid with SUDs such as anxiety, depression, pain, and stress. A better understanding of the mechanisms influencing behavioral changes and drug use is critical in developing novel treatments for SUDSs. Targeting the microbiome as a therapeutic and diagnostic tool is a promising avenue of exploration. This review will provide an overview of the role of the gut-brain axis in a wide range of SUDs, discuss host and microbe pathways that mediate changes in the brain’s response to drugs, and the microbes and related metabolites that impact behavior and health within the gut-brain axis.

物质使用障碍（SUDs）是一场重大的公共卫生危机。在全球范围内，5.4%的全球疾病负担归因于物质使用障碍和酒精使用，还有更多人将精神活性物质用于娱乐。物质使用障碍通常与合并症相关，会导致大脑功能和生理反应发生变化。越来越多的证据呼吁对物质使用障碍的治疗和诊断采取精准方法，而肠道微生物组正逐渐成为此类障碍的一个影响因素。在过去几个世纪里，现代生活方式、饮食和医疗保健改变了生活在我们体内和体表的微生物的健康状况；随着我们的成长，我们的饮食和生活方式决定了哪些微生物繁盛，哪些微生物消失。抗生素治疗的增加，其中许多抗生素干预发生在微生物组正常发育的早期生命阶段，改变了正在发育的微生物群落。微生物组与物质使用障碍之间以及微生物组与通常与物质使用障碍共病的状况（如焦虑、抑郁、疼痛和压力）之间已经建立了联系。更好地理解影响行为改变和药物使用的机制对于开发针对物质使用障碍的新疗法至关重要。将微生物组作为一种治疗和诊断工具是一个有前景的探索途径。这篇综述将概述肠 - 脑轴在多种物质使用障碍中的作用，讨论介导大脑对药物反应变化的宿主和微生物途径，以及在肠 - 脑轴内影响行为和健康的微生物和相关代谢物。