--- topic: "Manuka Honey" title: "Antibacterial Properties and Healing Uses" order: 1 description: "How manuka honey's uniquely high methylglyoxal content gives it exceptional antibacterial and wound-healing properties beyond ordinary honey" question: "Does manuka honey really heal wounds and kill bacteria?" answer: "Medical-grade manuka honey may help stubborn wounds heal, but the evidence is mostly lab studies and case series, and using it internally is unproven." actions: - "For wounds, use medical-grade honey (UMF 10+) on clean wounds or in impregnated dressings, changed every 1–3 days, under clinical guidance." - "Check the label for a UMF or MGO rating from a verified New Zealand producer; the market has documented adulteration." - "Internal use is unproven; if you try it, 1–2 teaspoons daily is typical, and heat above 40°C degrades MGO." cautions: - "Never give honey to infants under 12 months because of botulism risk." - "People with bee product allergies should use caution, and diabetics should count it as sugar (glycemic index about 54–56)." - "Manuka honey is not a replacement for standard H. pylori antibiotic therapy; the clinical evidence is a three-patient case series [3]." confidence: 2 confidenceNote: "Mostly laboratory antibacterial tests, a three-patient H. pylori case series, and case-series reports of dressings; no randomized trials are described." evidenceSummary: rctCount: 0 metaAnalysisCount: 1 replicated: false newestStudyYear: 2020 references: - id: "1" pmid: "18210383" title: "Identification and quantification of methylglyoxal as the dominant antibacterial constituent of Manuka (Leptospermum scoparium) honeys from New Zealand" authors: "Mavric E, Wittmann S, Barth G, Henle T" year: 2008 journal: "Molecular Nutrition and Food Research" - id: "2" pmid: "8308841" title: "Susceptibility of Helicobacter pylori to the antibacterial activity of manuka honey" authors: "Al Somal N, Coley KE, Molan PC, Hancock BM" year: 1994 journal: "Journal of the Royal Society of Medicine" - id: "3" pmid: "10656024" title: "Manuka honey against Helicobacter pylori" authors: "McGovern DP, Abbas SZ, Vivian G, Dalton HR" year: 1999 journal: "Journal of the Royal Society of Medicine" - id: "4" pmid: "31652284" title: "Antibacterial activity of varying UMF-graded Manuka honeys" authors: "Girma A, Seo W, She RC" year: 2019 journal: "PLoS One" - id: "5" pmid: "28901255" title: "Health Benefits of Manuka Honey as an Essential Constituent for Tissue Regeneration" authors: "Niaz K, Maqbool F, Bahadar H, Abdollahi M" year: 2017 journal: "Current Drug Metabolism" - id: "6" pmid: "33142845" title: "Clinical Significance of Manuka and Medical-Grade Honey for Antibiotic-Resistant Infections: A Systematic Review" authors: "Nolan VC, Harrison J, Wright JE, Cox JAG" year: 2020 journal: "Antibiotics (Basel)" --- Manuka honey is produced by bees that feed on the flowers of the manuka tree (*Leptospermum scoparium*), native to New Zealand and parts of Australia. Unlike ordinary honey, it contains extraordinarily high levels of methylglyoxal (MGO) — a compound that gives it a potent, peroxide-independent antibacterial effect that remains active even in wound environments [1]. It has been used medicinally for wound care, gut support, and infection prevention, and is now studied as an adjunct treatment in hospital settings for antibiotic-resistant bacteria [4]. The UMF (Unique Manuka Factor) rating on the label reflects the concentration of MGO: higher numbers are meant to indicate more MGO, although one laboratory study suggested that UMF alone may not be a reliable indicator of antibacterial effect [4]. Medical-grade manuka honey (UMF 10+ or MGO 263+) is the tier used in most clinical research. ## What Makes Manuka Honey Different All honey contains hydrogen peroxide (H₂O₂), which gives it mild antibacterial properties. Manuka honey has this too, but its defining characteristic is methylglyoxal (MGO), found at concentrations up to 100 times higher than in conventional honey [1]. MGO is formed naturally in the nectar of manuka flowers and accumulates during ripening. MGO works by a process called glycation — it binds to amino groups on bacterial proteins, causing them to lose function and leading to cell death. This mechanism is effective against both gram-positive and gram-negative bacteria, including difficult-to-treat organisms like *Staphylococcus aureus*, *Pseudomonas aeruginosa*, and methicillin-resistant *S. aureus* (MRSA) [4]. Crucially, MGO-mediated antibacterial activity is not neutralized by catalase (as hydrogen peroxide-based activity is) and remains effective in the presence of wound exudate — making it particularly useful in clinical wound care settings [5]. ## Wound Healing Medical-grade manuka honey has been used in certified wound dressings approved by health authorities in the US, EU, and Australia. The evidence supports its use for: - **Chronic wounds and ulcers**: Manuka honey promotes a moist wound environment, reduces inflammation, debrides necrotic tissue, and prevents biofilm formation. - **Burns and surgical wounds**: Studies show accelerated epithelial regeneration and reduced scarring compared to conventional antiseptic treatments [5]. - **Antibiotic-resistant infections**: Clinical settings have used manuka-impregnated dressings against MRSA wound infections when standard antibiotics have failed. Beyond direct antimicrobial action, manuka honey stimulates tissue regeneration by modulating immune signaling, promoting fibroblast proliferation, and supporting collagen deposition [5]. ## Gut Health and H. pylori *Helicobacter pylori* is the primary bacterial cause of peptic ulcers and a major risk factor for gastric cancer. Laboratory studies showed that manuka honey at just 5% concentration (v/v) completely inhibited *H. pylori* growth within 72 hours [2]. A follow-up clinical note documented three cases where supplementary manuka honey helped reduce *H. pylori* colonisation alongside conventional therapy [3]. While manuka honey is not a replacement for standard antibiotic eradication therapy, some clinicians include it as a supportive measure, particularly in patients with antibiotic resistance or those seeking complementary approaches. Its urease-inhibiting properties (via MGO) may help limit bacterial colonisation of the stomach lining. ## Understanding UMF and MGO Ratings The UMF grading system and MGO labelling measure the same underlying compound: | UMF Rating | MGO (mg/kg) | Suggested Use | |------------|-------------|---------------| | 5+ | ~83 | General immune and gut support | | 10+ | ~263 | Wound care, active H. pylori support | | 15+ | ~514 | Clinical-grade, MRSA, chronic wounds | | 20+ | ~829 | Hospital-grade wound applications | Girma et al. (2019), however, reported in *PLoS One* that, paradoxically, antibacterial activity did not rise with UMF grade across 128 wound culture isolates: lower-UMF honeys generally had lower minimum inhibitory concentrations (MICs) than higher-UMF honeys, and the authors concluded that the UMF value by itself may not be a reliable indicator of antibacterial effect [4]. ## How to Use Manuka Honey - **Internally (gut support)**: 1–2 teaspoons daily, ideally on an empty stomach, dissolved in cool water or taken directly. Heat above 40°C degrades MGO. - **Topically (wound care)**: Apply medical-grade manuka honey (UMF 10+ minimum) directly to clean wounds, or use commercially available manuka-impregnated dressings. Change dressings every 1–3 days. - **Oral health**: Manuka honey gel products are used for gingivitis and oral ulcers (canker sores). See our [honey page](/honey) for context on regular honey's health properties, and our [probiotics page](/probiotics/gut-microbiome) for related gut health support. ## Evidence Review ### Active Compound Identification The landmark study by Mavric et al. (2008), published in *Molecular Nutrition and Food Research*, established methylglyoxal as manuka honey's defining antibacterial compound [1]. Analyzing six New Zealand manuka honey samples, the researchers found MGO concentrations ranging from 38 to 761 mg/kg — up to 100-fold higher than in conventional honey samples. Activity was confirmed as peroxide-independent by comparing results before and after catalase treatment, demonstrating that the non-peroxide fraction of manuka honey was responsible for its superior antimicrobial efficacy. ### Spectrum of Antibacterial Activity Girma et al. (2019) assessed UMF-graded manuka honeys in what they describe as a limited sampling [4]. Testing UMF 5+, 10+, and 15+ honeys from the same manufacturer against 128 isolates from wound cultures — including staphylococci (among them methicillin-resistant *S. aureus*), *Pseudomonas aeruginosa*, and Enterobacteriaceae — the team determined MIC values using the broth microdilution method. All grades showed antibacterial activity, including against multi-drug resistant organisms, with more potent activity overall against gram-positive than gram-negative bacteria. Notably, higher UMF did not mean lower MICs: lower MICs were seen with UMF 5+ honey than with UMF 10+ honey for staphylococci and *P. aeruginosa* (p<0.05), and with UMF 10+ compared with UMF 15+ (p=0.01), while for Enterobacteriaceae the MIC values were significantly lower for UMF 5+ or UMF 10+ than for UMF 15+ honey (p<0.01). MIC50 against staphylococci was 6%, 7%, and 15% for UMF 5+, 10+, and 15+ honey, respectively. The authors noted that, in their limited sampling, honeys with lower UMF values paradoxically showed increased antimicrobial activity, presumably due to changes in the honey's MGO content over time, and that the UMF value by itself may not be a reliable indicator of antibacterial effect. ### H. pylori Inhibition Al Somal et al. (1994) were among the first to demonstrate manuka honey's efficacy against *H. pylori* in laboratory conditions [2]. Using gastric biopsy-derived isolates, they showed complete inhibition of visible growth at 5% (v/v) manuka honey over a 72-hour incubation. The antibacterial activity was confirmed as non-peroxide-dependent, consistent with MGO-mediated mechanisms rather than the hydrogen peroxide activity shared with ordinary honey. McGovern et al. (1999) subsequently reported a small clinical series of three patients with endoscopically confirmed *H. pylori* infection who incorporated manuka honey as a supplementary measure alongside conventional therapy [3]. While these cases were descriptive rather than randomized, they helped establish clinical interest in manuka honey for gastrointestinal *H. pylori* management. Larger controlled trials remain lacking; current evidence supports manuka honey as an adjunct rather than a first-line treatment. ### Wound Healing and Tissue Regeneration Niaz et al. (2017), reviewing the tissue regeneration evidence in *Current Drug Metabolism*, outlined multiple mechanisms by which manuka honey promotes wound healing [5]: MGO and its precursor glyoxal (GO) exert immunomodulatory effects that accelerate the inflammatory-to-proliferative phase transition; honey's low pH and high osmolarity create an inhospitable environment for bacteria while maintaining tissue hydration; and polyphenolic components support fibroblast activity and collagen synthesis. The review noted that medical-grade manuka honey dressings have demonstrated effectiveness in published case series for diabetic foot ulcers, pressure ulcers, and post-surgical wound dehiscence — often in situations where standard wound care had failed to promote healing. ### Biofilm Disruption A significant and growing body of in vitro evidence demonstrates manuka honey's ability to disrupt established bacterial biofilms — dense communities of bacteria encased in protective polysaccharide matrices that are notoriously resistant to conventional antibiotics. MGO appears to inhibit biofilm formation and penetrate existing biofilms, compromising bacterial signalling (quorum sensing) and reducing biofilm viability [6]. This property is clinically relevant because chronic wound infections and catheter-associated infections frequently involve biofilm-forming organisms. ### Safety and Limitations Manuka honey is generally safe for most adults and children over 12 months. It is contraindicated in infants under 12 months due to risk of botulism spores, as with all honey products. People with bee product allergies should use caution. For diabetic individuals using it internally, the glycaemic impact (manuka honey has a GI of approximately 54–56, similar to other honeys) should be factored into dietary planning. Clinical evidence for internal use in human trials remains limited primarily to in vitro and small observational studies; the strongest evidence base is for topical wound care applications. Sourcing matters significantly: products should carry UMF or MGO certification from verified New Zealand producers, as the manuka honey market has documented issues with adulteration.