For centuries, honey has been known to have antimicrobial properties, and has been used to treat a variety of ailments.
This medicinal value, which is exhibited by many types of honey, is believed to come from features such as honey’s acidity (low pH), high natural sugar concentration, and the presence of bacteriostatic and bactericidal compounds such as hydrogen peroxide, antioxidants, lysozyme, polyphenols, phenolic acids, flavonoids, and bee peptides. These features are sometimes collectively referred to as honey’s ‘peroxide’ activity.
New Zealand Manuka tree (Leptospermum scoparium) have additional antimicrobial activity, above and beyond (up to 100x more) plus what is contributed by the above features.
For several years, the cause of this ‘non-peroxide activity’ (NPA) wasn’t well understood and the term. Then, in 2006, scientists in Germany published research showing that manuka honey’s ‘non-peroxide’ antimicrobial activity (NPA) was closely related to the presence of the compound methylglyoxal (MGO). The relationship between MGO levels and NPA in New Zealand manuka honey was further demonstrated by researchers at Waikato University in a paper  that they published in 2008 (with correction in 2009).
Amazing stuff, Thanks MGO we love you and all your goodness.