Manuka Honey's Antibacterial Power Extends Beyond Sugar and MGO, Aston University Study Finds
核心洞察
Aston University researchers demonstrated that manuka honey's antimicrobial activity against respiratory pathogens cannot be replicated by sugar and methylglyoxal (MGO) alone.
All five UMF grades tested inhibited bacterial growth, with activity increasing alongside UMF, and methicillin-resistant Staphylococcus aureus (搜索) (MRSA) proved especially vulnerable.
The findings suggest additional bioactive compounds, or interactions between compounds, drive the honey's antibacterial effects, pointing toward new approaches against antimicrobial resistance.
New research at Aston University has shown that a variety of compounds is responsible for the antimicrobial action of manuka honey, not just the sugar content and methylglyoxal (MGO) alone, as previously thought. The study, led by Dr Jonathan Cox, a senior lecturer in biosciences at Aston University and head of the Mycobacterial Research Group, was conducted in partnership with scientists at New Zealand manuka honey producer Comvita Limited (搜索).
The work addresses a pressing clinical challenge: as many bacteria become increasingly resistant to antibiotics, new approaches and treatments are required. Manuka honey has already been proven effective against numerous disease-causing bacteria and, importantly, has so far not been associated with the development of resistance in the same way as antibiotics, making it a subject of growing interest for healthcare applications.
Testing Across UMF Grades and Respiratory Pathogens
The researchers tested honey with different Unique Manuka Factor (UMF) ratings, which range from 5+ to 20+ and represent a measure of the amount of MGO in the honey while guaranteeing compliance with the New Zealand government regulatory standard. The UMF grading system is independently certified and incorporates measurements of MGO, leptosperin and dihydroxyacetone, alongside tests confirming the absence of adulteration.
Working with Comvita, the study authors tested five grades of manuka honey against four bacteria responsible for serious respiratory illness: methicillin-susceptible and methicillin-resistant Staphylococcus aureus (搜索) (MRSA), Klebsiella pneumoniae (搜索) and Pseudomonas aeruginosa (搜索). All grades of honey inhibited bacterial growth, and the effect grew stronger as UMF increased. The two staph strains, including drug-resistant MRSA, were especially vulnerable, requiring far less honey to stop their growth than the two more hardy Gram-negative species.
Sugar and MGO Alone Cannot Explain the Effect
A central question the researchers set out to answer was why manuka honey works better than ordinary honey, given that both are essentially concentrated sugar solutions capable of dehydrating bacterial cells through osmotic stress. To test this, they compared the honey against a sugar solution matched to its exact carbohydrate makeup. In every case, the honey suppressed bacterial growth far more effectively than sugar alone, indicating that osmotic pressure could not be the whole story.
The team also tested artificial formulations containing equivalent concentrations of sugar and MGO, but the antimicrobial effect could not be replicated. When they created solutions containing MGO at concentrations matching those naturally found in each honey grade, those solutions had some antibacterial effect, but consistently less than the whole honey. The gap was especially pronounced against the two Gram-negative bacteria, which the MGO-only solutions struggled to suppress even at high concentrations.
Taken together, the findings suggest that manuka honey's antibacterial power comes from a combination of factors — sugar content, MGO and other, less-understood compounds in the honey matrix — rather than any single ingredient.
Toward Honey-Derived Therapeutics
The team are continuing to work closely with Comvita to identify and characterise the additional compounds responsible for the enhanced antimicrobial activity found in higher UMF manuka honey, and to determine how the compounds interact. Understanding these active components may support the development of more effective honey-derived therapeutics and antimicrobial products.
"Manuka honey is often viewed through the lens of a single compound, methylglyoxal, but our findings show that the story is far more complex," Dr Cox said. "High-grade manuka honey appears to derive its antimicrobial activity from a combination of factors working together, and understanding those interactions could help unlock new approaches to tackling infection in an era of increasing antimicrobial resistance."
"It turns out, the very nature of manuka honey, in all its complexity, may hold a powerful solution to the emerging global AMR crisis. We just need to learn how best to use it," Dr Cox added.
Dr Jackie Evans, chief science officer at Comvita Limited (搜索), noted: "Manuka honey has long been recognized for its unique antimicrobial properties. This exciting new research shows that MGO is only part of the story. Comvita is proud to be at the forefront of manuka honey science, and while this is early-stage research, it highlights the importance of understanding the other bioactive compounds that contribute to its unique antimicrobial properties. Discoveries such as these are helping unlock the full potential of manuka honey."
The results appear in the journal Microbiology (Gemma J. Allcott et al. 2026, Microbiology 172 (8); doi: 10.1099/mic.0.001746).