Observational StudyThe Association of Microbiome Patterns With Chronic Opioid Use

The United States is in the midst of an opioid epidemic, with the number of opioid-related deaths having risen six-fold since 1999. Chronic pain imposes a tremendous economic burden of up to US$635 billion per year in terms of direct costs (such as the costs of treatment) and indirect costs (such as lost productivity and time away from work). We need to better understand individual characteristics that may put patients at risk for chronic opioid use. Recently, the relationship between gut microbiome and diseases of the central and peripheral nervous systems has received increasing attention. New evidence suggests that gut microbiota may also play a critical role in many types of chronic pain, including inflammatory pain, neuropathic pain, and opioid tolerance. Many signaling molecules derived from gut microbiota, such as pathogen-associated molecular patterns, metabolites, and neurotransmitters, act on receptors that regulate the peripheral and central sensitization, which in turn mediate the development of chronic pain. Gut microbiota-derived mediators serve as critical modulators for the induction of peripheral sensitization, directly or indirectly regulating the excitability of primary nociceptive neurons. Given the strong evidence supporting gut microbiome's involvement in pain pathways, there is a need to develop studies that characterize the differences in gut microbiome between chronic pain patients requiring opioids versus healthy controls. The objective of this proposal is to perform a pilot study measuring the predictive ability of the gut microbiome with chronic opioid use - this will then lay the groundwork to adequately power a larger funded prospective study.