Is Honey Antibacterial?


Is honey antibacterial, and if so where do it's antibacterial properties come from?

The short answer is:
Yes, scientists have demonstrated that honey's acidic pH and distinct chemical properties, make it effective against a range of bacteria.  Honey is already used in clinical settings, for example, in gels, ointments and dressings in wound care1.

Why Honey Is Antibacterial - The Reasons

  • Honey is acidic, and has a pH that hampers the growth of micro-organisms.  
  • Honey also has a low water to high sugar content, and contains a potent inhibitor of bacterial growth: hydrogen peroxide.  You can read about how these qualities of honey work together to inhibit bacteria on my page: Does Honey Go Bad?
  • Honey contains Bee Def-1, which is an antibacterial peptide2.  
  • Phenolic compounds found in honey may also contribute to its antibacterial activity2. 

All of the above elements are present in honey depending on the source of nectar, bee type, and storage2. 

Which bacteria can honey fight?

Research is ongoing, however, a review by Almasaudi (2021)2 and by McLoone et al (2016)1 provide examples.

According to the above reviews, honey has been demonstrated to inhibit (among others) the following bacteria:

  • Methicillin-resistant Staphylococcus aureus (MRSA)
    Can potentially cause serious infections.
  • Pseudomonas aeruginosa: Can cause infections in the blood, lungs (pneumonia), or other parts of the body after surgery2.
  • Escherichia coli: 
    Some strains can cause diarrhea, while others cause urinary tract infections, respiratory illness, pneumonia, and other illnesses2.
  • Streptococcus pyogenes: 
    A cause of cellulitis, impetigo, and necrotizing fasciitis.
  • Salmonella choleraesuis and Salmonella zyphimurium:
    Important causes of reportable food-borne infection.
  • Enterobacter aerogenes:
    A Gram-negative bacteria which can cause infections on hospital wards.

Can honey help combat harmful fungi, viruses as well as bacteria?

Bacteria are one form of microbe, but there are other types which are harmful to humans. 

Honey has been shown to inhibit some fungi and viruses, and again, the reviews quoted provide examples, some of which are listed below. Additional examples of my own are covered in-depth on other pages of this website.

Fungi:

  • Trichophyton mentagrophyte: 
    A cause of ringworm.
  • Epidermophyton floccosum:
    The cause of fungal infections, such as athlete's foot3.
  • Candida albicans:
    According to the McLoone review, only one honey is mentioned to have demonstrated efficacy against Candida albicans (interestingly, not Manuka!).  See below.
  • Other fungi:
    Other fungi microbes that cause various skin infections, including Microsporum canis, Microsporum gypseum, Trichophyton rubrum, and Trichophyton tonsurans.


Viruses:

  • Varicella zoster virus:
    Some antiviral activity has been demonstrated in vitro against this virus.
    (Varicella zoster virus causes chicken pox4).
  • Herpes virus
    Various studies describe honey's efficacy in treating the herpes virus, for both cold sores (labial herpes) and genital herpes.  Please see Honey For Cold Sores.

Are all honeys as effective against the same microbes?

No, different honey varieties vary in their level of antibacterial activity, and even different batches of the same honey variety may not be uniform in their efficacy levels against some microbes1. 

For example, Tualang honey is a multi-floral honey that can vary significantly between batches.

The reason for the variance is that the nectar gathered by bees contains some of the chemical properties of the plant from which it was gathered.  Therefore, the natural chemical composition and antibacterial qualities of the honey, are contingent upon its botanical origin2.

This may result in differing levels of efficacy against bacteria, fungi and other microbes, for certain honeys.

For example, McLoone et al state that whilst C. albicans was inhibited by Jujube honey, a honey obtained from bee keepers in Al-baha, Saudi Arabia.  Jujube honey is made  by bees feeding on the plant Ziziphus jujuba.

By contrast, C. albicans was not inhibited by Manuka honey, nor a range of Slovenian honeys. 








References

1. Pauline McLoone, Mary Warnock, Lorna Fyfe, Honey: A realistic antimicrobial for disorders of the skin, Journal of Microbiology, Immunology and Infection, Volume 49, Issue2, 2016, Pages 161-167, ISSN 1684-1182, https://doi.org/10.1016/j.jmii. 2015.01.009.
2. Saad Almasaudi, The antibacterial activities of honey, Saudi Journal of Biological Sciences, Volume 28, Issue 4, 2021, Pages 2188-2196, ISSN 1319-562X, https://doi.org/10.1016/j.sjbs.2020.10.017.
3. Center For Disease Control And Infection
4. University of Adelaide: Epidermophyton - Epidermophyton floccosum
5. BMJ - British Medical journal Acute varicella-zoster - Symptoms, diagnosis and treatment | BMJ Best Practice.