(Based on the review article by a multinational team of researchers: “Implications of the gut microbiome in spinal cord injuries,” Jeyaraman et al., Frontiers in Surgery, 2025)
For years, research into spinal cord injury (SCI) has focused mainly on the damaged nerves themselves. But scientists are now realising that another part of the body—the gut—may be just as important in influencing recovery.
The gut–brain axis
Our gut is home to trillions of bacteria and other microbes that help digest food, produce vitamins and regulate our immune system. Collectively, they’re known as the gut microbiome. This community constantly communicates with the brain and spinal cord via what researchers call the gut–brain axis.
Following an SCI, gut function often slows down, leading to constipation, changes in diet, and frequent antibiotic use—all of which can disturb this delicate microbial balance. The result is dysbiosis—a loss of beneficial bacteria such as Lactobacillus and Bifidobacterium and an overgrowth of inflammatory or infection-causing species.
Why this matters
These microbial changes don’t just stay in the gut. They can increase gut permeability (“leaky gut”), allowing bacterial toxins to enter the bloodstream and trigger widespread inflammation. This inflammation can, in turn, worsen nerve damage, slow tissue repair, and contribute to chronic pain. It may also affect mood and energy levels through chemical messengers that travel along the gut–brain axis.
In higher-level spinal injuries, the nerve pathways that normally allow two-way communication between the gut and brain can be severely disrupted. This means the brain can no longer fully regulate gut movement, blood flow or immune activity in the intestines—setting the stage for microbial imbalance and inflammation. While the connection isn’t completely severed (hormonal and vagus-nerve signalling continue), it becomes far less coordinated, amplifying many of the gut-related challenges faced after SCI.
Promising approaches
The review highlights several ways to restore microbial balance and support healing:
- Probiotics and prebiotics: Certain probiotic strains, such as Lactobacillus rhamnosus and Bifidobacterium longum, have anti-inflammatory and neuroprotective effects in animal studies. Prebiotic fibres (like inulin) can “feed” these beneficial bacteria.
- Diet: High-fibre, plant-based diets encourage bacteria that produce short-chain fatty acids (SCFAs)—molecules that calm inflammation and promote nerve protection.
- Faecal microbiota transplantation (FMT): Though still experimental, FMT has shown in laboratory models that transferring healthy gut bacteria can reduce inflammation at the injury site and improve neurological recovery.
The road ahead
While most current findings come from pre-clinical studies, the evidence strongly supports further exploration. Future clinical trials will need to test whether microbiome-targeted treatments can meaningfully improve recovery, reduce infections, or ease complications such as pressure sores and urinary tract infections in people with SCI.
In summary
The gut microbiome represents a promising new frontier in spinal cord injury research. By caring for the gut, we may one day enhance the body’s ability to repair the spinal cord itself—an exciting prospect that links nutrition, neurology and microbiology in ways we are only beginning to understand.