Neuropathic pain is a disabling condition that affects 1-2 per cent of patients in the general population. Central sensitization of the secondary nociceptive neurons in the spinal dorsal horn is thought to be the key process in the initiation of neuropathic pain. Emerging studies have demonstrated the neuromodulatory functions of gut microbiota. However, the molecular mechanism mediating the analgesic effect associated with gut microbiota depletion has not been fully defined.
In a series of experiments, the investigators will determine the effect of gut microbiota depletion on hyperalgesia/allodynia in murine models of neuropathic pain. The immune microenvironment and transcriptomic profile of the spinal dorsal horn will be characterized. Finally, the pro-nociceptive effect of gut microbiota in germ-free mice with or without microbiota reconstitution will be determined.
Efficacy data from this animal study will provide pre-clinical evidence that paves the way for future clinical trials on gut microbiota manipulation with antibiotic or probiotic treatment in the management of neuropathic pain.
Professor Matthew Chan, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China.
The project was awarded $A70,000 through the ANZCA research grants program for 2022.
Neuropathic pain, such as postherpetic neuralgia, is a disabling condition that affects 1-2% of patients in the general population. The underlying mechanisms is currently unclear. Consequently, physicians are limited in their ability to manage neuropathic pain. The purpose of this study was to determine the role of gut microbiota in the development of neuropathic pain, by modulating infiltration of immunity-related cells and neural pathways after neuronal injury.
We have identified a gut bacterium that was depleted in patients with chronic pain. This bacterium also enhanced pain signal transmission through the vagus nerve to the brain to suppress the brain region that is involved in pain perception.
Overall, the experiments established a microbiota-based model for assessing chronic pain and identified a potential pain-alleviating probiotic. A further clinical trial to test this probiotic in preventing and managing chronic pain is warrant.
A manuscript has been submitted to a peer-review journal for consideration. We have obtained US provisional patent - The Novel probiotics and their analgesic effect on chronic neuropathic pain. (63/568,487)