A dash of vanilla boosts power of antibiotics

Pairing vanilla with antibiotics could help drugs that were written off, having lost the war to resistant bacteria, become useful again, researchers from the European Molecular Biology Laboratory (EMBL) reported last week.

When they paired vanillin, the compound that gives vanilla its distinctive taste with spectinomycin, it helped the antibiotic enter bacterial cells and inhibit their growth.

Spectinomycin used to treat gonorrhoea in the past, but was shelved after bacteria became resistant to it. Now scientists say that when combined with vanilla, it could become clinically relevant again.

Scientists from EMBL tested the effect of 3,000 drug combinations on three disease-causing bacteria, and found that the effectiveness of antibiotics can be altered by combining them with other antibiotics, other drugs or with food additives such as vanilla.

While some combinations stopped antibiotics from working to their full potential, others made them more powerful, so much so that they were able to fight resistant bacteria.

Vanillin combined with spectinomycin was one of the most effective and promising synergies identified, said first author Ana Rita Brochado.

Curiously, vanillin lessened the effect of many other types of antibiotics, working in a similar way to aspirin to decrease their activity. And though its effects in human cells have not been tested, they are likely different, the researchers noted.

Many of the drug combinations tested lessened the effects of antibiotics, but more than 500 pairings improved antibiotic outcome against different bacterial species. A selection of these positive pairings tested in multi-drug resistant bacteria isolated from infected hospital patients was found to improve antibiotic effects.

Researchers noted that drug combinations that decrease the effect of antibiotics could also be beneficial to human health.

“ Normally, antibiotics target healthy bacteria as well, but the effects of these drug combinations are highly selective, and often only affect a few bacterial species. In the future, we could use drug combinations to selectively prevent the harmful effects of antibiotics on healthy bacteria. This would also decrease antibiotic resistance development, as healthy bacteria would not be put under pressure to evolve antibiotic resistance, which can later be transferred to dangerous bacteria,” said EMBL leader Nassos Typas, who led the study.

Researchers noted that understanding the general principles behind drug to drug interactions will help more rational selection of drug pairs and may be broadly applied to other therapies. The next step is investigations in mice and clinical studies to test the effectiveness of particular drug combinations in humans.