Maple Syrup: New Way to Fight Antibiotic-Resistant Bacteria?
Maple syrup may help fight disease-causing bacteria, including antibiotic-resistant strains that often grow in health-care settings, says a study published online in Applied and Environmental Microbiology. Concentrated extracts of maple syrup combined with antibiotics significantly reduced the growth of four common bacterial strains and bacterial communities called biofilms, the study found. Bacterial biofilms accumulate on medical surfaces and devices, such as catheters and artificial joints, and are responsible for many antibiotic-resistant hospital infections, research has shown.
The maple-syrup extracts appeared to damage the outer membrane of bacterial cells, increasing their susceptibility to antibiotics, and to disable cellular mechanisms called efflux pumps associated with antibiotic resistance, the researchers said. The extracts also reduced the activity of genes in the bacteria linked to antibiotic resistance. Maple syrup contains plant-based compounds called phenols that have exhibited antioxidant and anti-cancer properties in previous studies, according to researchers. Maple syrup may reduce the dose of antibiotics needed to kill biofilms, they said.
The study, at McGill University in Montreal, used concentrated maple-syrup extracts developed from syrup purchased at local markets in August 2013. The extracts and four phenols isolated from maple syrup were tested separately and in various combinations, with and without the antibiotic ciprofloaxin, against Escherichia coli, or E.coli; Proteus mirabilis, a common cause of urinary-tract infections; and two strains of Pseudomonas aeruginosa, associated with hospital-acquired infections. Maple-syrup extract alone suppressed the growth of biofilms for all four strains. But pairing the extract with ciprofloaxin reduced E. coli and P. mirabilis biofilm formation by about 70% and the two P. aeruginosa strains by 83% and 54%, compared with control cultures treated with just ciprofloaxin. Of the phenols tested, only catechol, when combined with ciprofloaxin, significantly reduced the growth of all four bacterial strains. Catechol may be responsible for maple syrup%u2019s antimicrobial properties, the study suggests.
Caveat: Maple-syrup extracts combined with antibiotics haven%u2019t been tested in human trials.