Probiotics could aid recovery from spinal cord injury

Spinal cord injury causes profound changes in the types of bacteria normally found in the gut, and counteracting these changes with probiotics could aid patients' recovery from spinal cord injuries, suggests new research.

"The trillions of microbes that exist in the gastrointestinal tract have emerged as pivotal regulators of human development and physiology," said principal investigator Phillip Popovich, Professor at Ohio State University's Neurological Institute.

"Spinal cord injuries cause dramatic shifts in the types of bacteria normally found in the gut, resulting in dysbiosis (microbial imbalance), which can cause or contribute to neurologic disease," Popovich noted.

The researchers found that spinal cord injury significantly altered the gut microbiome of mice, inducing the migration of gut bacteria into other tissues of the body and the activation of proinflammatory immune cells associated with the gut.

Mice that showed the largest changes in their gut bacteria tended to recover poorly from their injuries. 

Indeed, when mice were pretreated with antibiotics to disrupt their gut microbiomes before spinal cord injury, they showed higher levels of spinal inflammation and reduced functional recovery. 

In contrast, when injured mice were given daily doses of probiotics to restore the levels of healthy gut bacteria, they showed less spinal damage and regained more hindlimb movement.

"Although paralysis and loss of neurologic function are well-known consequences of spinal cord injury, the current data reveal a previously unappreciated role for spinal cord injury in changing the gut microbiome with reciprocal effects on the magnitude of functional recovery and spinal cord neuropathology," study first author Kristina Kigerl from Ohio State University said.

The study, published online in the Journal of Experimental Medicine, suggests that commercially available probiotics, when given after spinal cord injury, protect the microbiome and confer neuroprotection, improve neurological recovery and elicit a protective immune response in gut-associated lymph tissue (GAlT).

These data will help shape future pre-clinical and clinical research programmes focused on understanding the importance of the gut-immune-central nervous system axis in recovery from spinal cord injury, Popovich said.