Abstract and Introduction
The gut microbiome plays critical roles in human health and disease. Recent studies suggest it may also be associated with chronic pain and postoperative pain outcomes. In animal models, the composition of the gut microbiome changes after general anesthesia and affects the host response to medications, including anesthetics and opioids. In humans, the gut microbiome is associated with the development of postoperative pain and neurocognitive disorders. Additionally, the composition of the gut microbiome has been associated with pain conditions including visceral pain, nociplastic pain, complex regional pain syndrome, and headaches, partly through altered concentration of circulating bacterial-derived metabolites. Furthermore, animal studies demonstrate the critical role of the gut microbiome in neuropathic pain via immunomodulatory mechanisms. This article reviews basic concepts of the human gut microbiome and its interactions with the host and provide a comprehensive overview of the evidence linking the gut microbiome to anesthesiology, critical care, and pain medicine.
In recent years, new insights into the composition and function of the human microbiome are shedding new light on many fields of clinical medicine. The human body hosts a wealth of bacterial species that play cardinal roles in its function in health and in many disease conditions. This role extends beyond mere associations, and a putative causal role of specific bacterial taxa and ensembles is constantly unraveling in fields ranging from gastroenterology to psychiatry. Until recently, little was known about the role the gut microbiome plays in anesthesiology and pain; however, new studies shed interesting light on the importance of the gut microbiome in these fields, paving the way for potential clinical applications. This review aims to summarize the key findings on the bidirectional interactions between the human body and the gut microbiome pertinent to anesthesiologists, intensivists, and pain physicians. We review the interaction of the gut microbiome with four distinct clinical domains, including effects of anesthetics and analgesics, perioperative outcomes, intensive care, and pain. For each domain, the results of preclinical and clinical studies are summarized.
Anesthesiology. 2022;137(1):93-108. © 2022 American Society of Anesthesiologists | Lippincott Williams & Wilkins