The overuse of antibiotics has caused the emergence of new resistant strains known as superbugs, which has now led to concern from public health officials across the world. However, a team of researchers from McGill University in Montreal, Canada think that the secret to fighting these bugs may lie in the sap of trees that are abundant across all of North America.

The study, published in Applied and Environmental Microbiology, found that concentrated maple syrup actually makes disease causing bacteria more susceptible to antibiotics. The researchers, led by Nathalie Tufenkji, a chemical engineering professor, made their discoveries from working with lab based colonies of bacteria but hope that their discovery will have the same effect on bacterial infections in human patients.

Maple syrup contains phenolic compounds, which are of considerable interest due to their antiseptic and antioxidant properties. These compounds play an important role in the growth of plants by helping them defend against pathogens.

For the study, researchers made an extract containing mainly phenolic compounds from maple syrup that was purchased at local markets in Montreal. They then tested this extract on a number of infection causing bacteria such as Escherichia coli and Proteus mirabilis. On its own, the maple syrup extract was mildly effective against the bacteria, but when combined with antibiotics, the maple syrup was even more effective.

The maple syrup extract and antibiotic combination was particularly effective at destroying biofilms - resistant communities that inhabit surfaces and are particularly hard to shift with antibiotics. Dental plaque is an example of a biofilm.

The researchers say that the maple syrup extract actually affects the bacteria in a number of different ways. One effect that the extract has on bacteria is to make their cell membranes more porous, allowing the antibiotics to enter the microbial cells much more easily. The maple syrup extrat also shuts down the "efflux pumps" that the bacteria uses to flush any of the antibiotics through the membrane out of the cell. The syrup also weakens the bacteria by reducing the expression of genes that are resistant to antibiotics and connected to more virulence.

According to the researchers, this study is the first step that proves the concept. But more work needs to be done. Researchers hope this is just the beginning and this study will lead to clinical trials so they can determine what affect maple syrup has on human patients taking antibiotics.

But Professor Tufenkji says the findings "suggest a potentially simple and effective approach for reducing antibiotic usage," and adds, "I could see maple syrup extract being incorporated eventually, for example, into the capsules of antibiotics."