Mānuka [ mā·nu·ka  ] Honey comes from the nectar of the flower of the Mānuka bush (Leptospermum scoparium) which is indigenous to New Zealand. It is the nectar and the bee that give this honey its unique properties. 

Mānuka honey has become one of the most researched honeys in the world. The research paper and peer review can be found here hyperlink https://www.umf.org.nz/umf-science/information-database/ 

Below are some interesting finding and research on Manuka:

Anti-influenza Viral Effects of Honey
Effectiveness of honey for symptomatic relief in upper respiratory tract infections: a systematic review and meta-analysis
Molecular Mechanisms of Natural Honey Against H. pylori Infection
The inhibitory effect of Mānuka honey on human colon cancer – Part 1
The inhibitory effect of Mānuka honey on human colon cancer – Part 2
Mānuka Honey-Induced Suppression of Human Breast Cancer Cells
Killing wound pathogens with Mānuka Honey dressings