BHU researchers advance bacteriophage therapy for diabetic foot ulcers

A wound that refuses to close—that stays open for months, then years, weeping and infected despite every antibiotic a doctor can prescribe—is a particular kind of torment. It damages the body, yes, but also the mind. Patients live with the constant threat of amputation, the smell, the pain that won't resolve. For decades, medicine had few answers once bacteria developed resistance to standard drugs. Now researchers at Banaras Hindu University say they have found one: bacteriophages, viruses that hunt and destroy bacteria where antibiotics fail.

Prof Gopal Nath and his team in the department of Microbiology at BHU's Institute of Medical Sciences have published findings showing that wounds taking months or years to heal can close in days or weeks. The distinction matters. A fresh wound—a cut, a surgical incision—follows a predictable path to recovery. But a chronic wound is something else entirely. It's a breach in skin or tissue that, after three months, has stalled. The body cannot repair itself. Infection sets in. Bacteria form biofilms, protective layers that antibiotics cannot penetrate. The wound persists. It recurs. Conventional treatment fails.

This is where bacteriophage therapy enters. Phages are viruses that infect bacteria and destroy them from within. They are not new—they were used before antibiotics existed—but they have been largely forgotten in the antibiotic age. Now, as bacteria grow resistant to drugs, phages are being reconsidered as a tool. Nath's team tested the approach in animals first. They exposed mice with infected wounds to phages targeting Pseudomonas aeruginosa, a common culprit in chronic infections. The phages worked. They then tested phage cocktails—mixtures of different phages—against methicillin-resistant Staphylococcus aureus in rabbits, another bacterium that laughs at standard antibiotics. Again, the phages cleared biofilms and allowed wounds to heal.

The animal results were encouraging enough to move to human trials. In one study, twenty patients with chronic non-healing ulcers lasting more than six weeks received topical phage therapy. Within weeks, their wounds closed completely. A second trial involved forty-eight patients with full-thickness wounds that had resisted conventional care for at least six weeks. Again, significant improvement followed. A third study focused on acute traumatic wounds—fresh injuries that had become infected. Patients treated with phages healed in roughly half the time required by conventional therapy. Across all trials, no adverse events were reported.

What makes this work is specificity. Phages target particular bacteria. A phage that kills Pseudomonas will not touch Staphylococcus. This means a doctor can match the phage to the infection, rather than hoping a broad-spectrum antibiotic will work. The research also found that phage therapy was effective regardless of whether a patient had diabetes, though diabetic patients did heal somewhat more slowly—a reminder that diabetes itself complicates recovery, independent of infection.

The implications are substantial. Diabetic foot ulcers are a leading cause of non-traumatic amputation worldwide. They carry psychological weight as well as physical: the wound that won't heal becomes a constant presence, a daily reminder of vulnerability. For patients whose infections resist antibiotics, the options narrow to amputation or chronic suffering. Bacteriophage therapy offers a third path. It is not a cure-all—the research is still early, the trials were small—but it is a tool that works when others fail. The findings have been published in the National Centre for Biotechnology Information, part of the U.S. National Institutes of Health, making them available to researchers and clinicians worldwide. What happens next depends on whether other institutions can replicate the results, whether regulatory pathways can accommodate phage therapy, and whether the approach can scale beyond the laboratory.