SAGE veterinarians treat wounds that are infected by bacteria that resist many first line antibiotics, just as physicians do in their human patients. When antibiotic resistance happens, SAGE Concord surgeon Lissa Richardson turns to honey, a substance that humans have used as a wound dressing since time immemorial.

Why Honey?

Honey has antimicrobial properties that make it an effective wound dressing, and our ancestors used it for centuries before pharmaceutical antibiotics were developed. When antibiotics became widely available during the 1960s, honey was dismissed as a “worthless but harmless substance,” according to researchers.[1] But as antibiotic resistance has become more common—and potentially deadly—the medical community has rediscovered honey, a complex mix of sugars, amino acids, phenolics, and other substances. The scale of honey usage is vast: Honey-based wound care products have been registered with medical regulatory authorities in Australia, Canada, the European Union, Hong Kong, New Zealand and the United States.[2]

All Honies are Not Created Equal

Different honey types derived from different flowering plants vary in their ability to kill bacteria.[3] At SAGE, Dr. Richardson uses manuka honey, which is produced by a species of bees that are native to New Zealand and Australia. Manuka honey is known for its superior antibacterial and healing properties.

In the mid-1980s, Professor Peter Molan of Waikato University in New Zealand began testing manuka honey on a range of bacteria species.[4] Molan found that even in low concentrations, manuka honey effectively killed harmful bacteria. Researchers pointed to the general make-up of honey: It’s high in sugar and has a low pH—an environment that bacteria find unfavorable. They also considered that honey produces hydrogen peroxide; but in manuka honey, the hydrogen peroxide levels were very low. Even when researchers diluted the manuka honey, it inhibited microbial growth.

More studies followed, and in 2008, researchers found that manuka honey contains methyl glyoxal (MGO). Additional studies have credited MGO for most—but not all—of the antibacterial activity in manuka honey.[5]

Questions Remain

After decades of research, manuka honey remains somewhat of a mystery. Because MGO can react with deoxyribonucleic acid (DNA), ribonucleic acid (RNA) and proteins, scientists have theorized that it could be toxic to mammalian cells.[6] But there is no evidence of damage to cells; rather conversely, manuka honey seems to promote wound healing.

In the paper “Therapeutic Honey: No Longer So Alternative,” researchers wrote: “How it exerts this apparently selective toxicity to bacterial cells is not known.”

“It’s been such a gift to us, mostly because of the antibacterial properties,” Dr. Richardson says. “We can take animals off injectable or oral antibiotics much sooner, or avoid them altogether in some cases. This way, we avoid having as much of the antibiotic resistance problems and can speed healing of our patients.”

Sources:

[1] Soffer, A., “Chihuahuas and laetrile, chelation therapy, and honey from Boulder, Colorado,” Archives of Internal Medicine (1976). Cited here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4837971/

[2] Irish, Julie, et al., “The Antibacterial Activity of Honey Derived from Australian Flora,” 2001. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3065476/

[3] Carter, Dee A., et al., “Therapeutic Manuka Honey: No Longer So Alternative,” Frontiers in Microbiology 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4837971/

[4] Carter, Dee A., et al., “Therapeutic Manuka Honey: No Longer So Alternative,” Frontiers in Microbiology 2016.

[5] Carter, Dee A., et al., “Therapeutic Manuka Honey: No Longer So Alternative,” Frontiers in Microbiology 2016.

[6] Kalapos, M.P., “The tandem of free radicals and methylglyoxal.”Chemico-Biological Interactions, 2008.Cited here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4837971/