A morning cup of coffee, considered by most people to be an innocuous habit, may interfere with the effectiveness of antibiotics, according to an international team of scientists who studied the interaction of caffeine with Escherichia coli (E. coli) bacteria.
The study found that caffeine can reduce the ability of bacteria to absorb certain drugs, including the popular antibiotic ciprofloxacin. This occurs by activating the Rob protein, which regulates the transport of substances in cells. As a result, the work of bacterial genes is changed and the system of entry of substances into the cell and their excretion is rebuilt.
According to bioengineer Ana Rita Broshadou of the University of Tübingen, “caffeine triggers a chain of events that leads to a decrease in the effectiveness of antibiotic therapy.” A similar effect was found only in E. coli, while the closely related Salmonella enterica did not have such a reaction.
This is called low-level antibiotic resistance. This is not direct resistance, where bacteria completely block the action of the drug, but rather hidden mechanisms that allow microorganisms to partially avoid the effects of the drug.
Despite the interesting findings, the researchers emphasize that the results have so far only been obtained in laboratory conditions. It is not known how relevant they will be to the human body and how much coffee must be consumed for the effect to manifest.
At the same time, scientists remind that excessive consumption of coffee or tea, especially very hot ones, can also be dangerous. Earlier, a study by the US National Cancer Institute showed that regular consumption of very hot drinks significantly increases the risk of esophageal cancer.
Further experiments should help to better understand how common drinks affect the effectiveness of antibiotics and whether patients should adjust their eating habits during treatment.