How honey fights infections: Türkiye’s research into antimicrobial properties

Honey has long been celebrated for its sweetness and health benefits, earning it the moniker “liquid gold.” From soothing cold symptoms to promoting wound healing, honey is praised for its anti-inflammatory, antioxidant, and antimicrobial properties. But what gives this sweet treat its medicinal power, and is there scientific merit behind these claims?

As it turns out, honey isn’t just a grocery store staple. It is also home to a diverse population of microorganisms, creating a local microbiome within the viscous substance. This microbial community raises several important questions when it comes to human consumption, health and safety.

Is honey safe to consume raw or pasteurized? And what factors influence its microbial composition and implications for human well-being?

Composition of honey, relationship to microbes

Honey is primarily composed of sugars, water, and various organic compounds produced by honeybees. While the Western honeybee, Apis mellifera, is the most commonly cultivated species for mass honey production, eight other recognized bee species also produce honey, including Apis cerana and Apis nigrocincta.

The process of honey production begins when bees collect nectar and honeydew from flowers, which they then enzymatically convert from maltose and sucrose into the primary sugars of honey: fructose and glucose.

This sugary mixture becomes home to various microorganisms, including Bacillus, Klebsiella, Saccharomyces, and Aspergillus. These microbes are introduced through the bee’s digestive tract and the environment, such as air, soil, dust, and plants. Factors like the honeybee’s microbiome, the floral source of nectar, geographic location and environmental conditions all influence the microbial diversity in honey.

Beneficial, undesirable microbes in honey

Some microbes found in honey can be beneficial. For example, certain bacteria produce lactic acid, contributing to honey’s acidity and its preservative qualities.

Other microbes, like Saccharomyces and Candida, may be undesirable, especially in honey with high moisture content, which can lead to spoilage.

The honeybee gut microbiome plays a crucial role in the processing and chemical composition of honey. Two major groups of lactic acid bacteria, Lactobacillus and Bifidobacterium, are present in honeybee guts worldwide. These bacteria help maintain honey’s acidity, probiotic nature, and antimicrobial peptides.

However, disturbances to these beneficial gut populations can harm the honeybee, leaving it vulnerable to infections and diseases, such as stonebrood, caused by the opportunistic fungus Aspergillus fumigatus.

Honey’s natural antimicrobial properties

Despite the presence of various microbes, honey’s natural composition creates an environment that resists microbial growth. Worker bees secrete an enzyme called glucose oxidase in their heads, which converts glucose into hydrogen peroxide (H2O2) and water.

During the honey-making process, this enzyme is mixed with nectar, and H2O2 remains trapped in the honey, contributing to its low pH and acting as a natural preservative. This acidic environment, along with honey’s high sugar and low moisture content, creates a natural barrier to bacterial growth.

The acidity of honey can vary based on the floral source of the nectar. Seasonal variations in flora and regional environmental factors also influence the microbial composition. One well-known type of monofloral honey, Manuka honey, produced from the nectar of the Leptospermum scoparium bush in New Zealand and Australia, has been celebrated for its antimicrobial and anti-inflammatory properties, thanks to a compound called Methylglyoxal (MGO). Research has shown that MGO contributes to honey’s antimicrobial effects, but other compounds like H2O2 and the osmotic effect also enhance its overall antimicrobial activity.

Risks and health concerns of honey consumption

While honey is widely considered safe for most people, there are risks associated with its consumption, especially for those with certain allergies. Raw honey, which retains more of its natural microbial diversity, may contain pollen that could trigger allergic reactions.

Additionally, raw honey can harbor the bacteria Clostridium botulinum, which produces a neurotoxin that causes botulism. This is particularly dangerous for infants under 1 year old, whose developing digestive systems may allow the bacteria to thrive, leading to severe illness or even death.

Health organizations recommend that children under 12 months of age should avoid consuming honey, whether raw or pasteurized.

In contrast, pasteurized honey undergoes high-heat processing, which reduces its microbial load but may also remove beneficial microbes that support gut health. The storage conditions of honey are also important, as exposure to moisture, heat, and air can promote microbial growth and spoilage.

Honey’s potential in medicine, future research

The fascinating microbiology of honey reveals a complex world of microorganisms that coexist within this sweet treat. Beyond its culinary appeal, honey offers promising health benefits, particularly in its antimicrobial properties.

While more research is needed to fully understand honey’s potential as a medicinal treatment, its natural composition, including its microbial diversity, continues to capture the interest of scientists.

Future studies may uncover even more about honey’s ability to support human health, particularly in the fields of wound healing, gut health, and antimicrobial resistance.

As honey research continues to expand, the “liquid gold” may one day play a more significant role in medicine than previously imagined.