Bacteria Causing Chronic Sinusitis Eradicated by Honey

Honey is very effective in killing bacteria in all its forms, especially drug-resistant biofilms that make treating chronic rhinosinusitis difficult, according to a new study.

Researchers at the University of Ottawa (Canada) tested in the laboratory the bactericidal effects of different honeys against both planktonic (single bacteria) and biofilm forms. The bacteria targeted were Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA) shown to be important factors in chronic rhinosinusitis, or inflammation of the sinuses and mucosa. The research involved Manuka honey from New Zealand and Sidr honey from Yemen; Clover and buckwheat honeys from Canada were dropped from the study when it was found they had no effect against the biofilms.

The study results showed that both Manuka and Sidr honeys were effective in killing 100% of the isolates in the planktonic form. For the biofilms, the bactericidal rate for Sidr honey was 63% for methicillin-susceptible SA (MSSA), 73% for methicillin-resistant SA (MRSA), and 91% for PA. The respective rates for Manuka honey were 82% against MSSA, 63% against MRSA, and 91% against PA. The researchers said that given the historical uses of honey in some cultures as a homeopathic treatment for bad wound infections, their findings may hold important clinical implications in the treatment of refractory chronic rhinosinusitis, and that an animal study will be conducted to check on the safety of a honey-water solution used to irrigate the nose. The study was presented at the 2008 annual meeting of the American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNSF), held during September 2008 in Chicago (IL, USA).

"The results are OK; it's a good effect. It killed 90% - 10 out of 11 isolates of Pseudomonas - so that's great because none of the antibiotics could do that,” said lead author and study presenter Talal Alandejani, M.D. "It's cheaper than any antibiotic. It doesn't cause side-effects. The nice thing about it, if you don't like it, you can just irrigate it out with water.”

The antibacterial properties of honey are the result of the low osmosis (honey is primarily a saturated mixture of two monosaccharides. This mixture has a low water activity; most of the water molecules are associated with the sugars and few remain available for microorganisms, so it is a poor environment for their growth); a hydrogen peroxide effect (honey chelates and deactivates the free iron, which starts the formation of oxygen free radicals produced by hydrogen peroxide present in Honey); and high acidity (honey has a pH between 3.2 and 4.5; this relatively acidic pH level prevents the growth of many bacteria).

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