In a recent study led by the Ohio State University, researchers find that spinal cord injury changes the type of bacteria living in the gut. These changes worsen the neurological damage and impair function recovery.
The finding is newly published in The Journal of Experimental Medicine.
The bacteria living in the gastrointestinal tract are grouped as the gut microbiome. Disruption of this microbial community, or dysbiosis, is linked to autoimmune diseases, such as multiple sclerosis and type I diabetes.
In the study, researchers found that mice showing the largest changes in their gut bacteria tended to recover poorly from their injuries.
When mice were pretreated with antibiotics to disrupt their gut bacteria before spinal cord injury, they showed greater of spinal inflammation and slower functional recovery.
On the contrary, when injured mice were given daily doses of probiotics to restore healthy gut bacteria, they showed less spinal damage and regained more leg movement.
Researchers suggest that the probiotics contained large numbers of lactic acid–producing bacteria. The probiotics could activate a type of gut-associated immune cell—regulatory T cells—that can suppress inflammation.
These regulatory T cells could prevent excessive damage to the spinal cord after injury. In addition, the probiotic bacteria may boost spinal cord recovery by secreting molecules that enhance neuronal growth and function.
These mechanisms can explain how disruption of the gut bacteria after injury harms the recovery and how probiotics can block or reverse these effects.
The finding highlights a previously ignored role for the gut-central nervous system–immune axis in helping with recovery after spinal cord injury. Future research will investigate how to apply the finding to clinical care.
Citation: Kigeri KA, et al. (2016). Gut dysbiosis impairs recovery after spinal cord injury. The Journal of Experimental Medicine, published online. DOI: 10.1084/jem.20151345.
Figure legend: This Knowridge.com image is credited to National Institute of Allergy and Infectious Diseases, National Institutes of Health.