It has been discovered that coffee can reduce the effectiveness of antibiotics.

Drinking a daily cup of coffee may weaken the effectiveness of some antibiotics, according to a new study.

An international team studied the response of Escherichia coli (E. coli) bacteria to caffeine and analyzed how it varies in response to antibiotics.

The study tested 94 different chemicals. About a third of these affected the activity of genes that regulate substances entering and exiting bacterial cells. But the most striking result came from caffeine, which caused E. coli to absorb less of certain antibiotics, particularly ciprofloxacin.

Low-Level Antibiotic Resistance

The researchers note that this effect should be considered in the context of “low-level antibiotic resistance,” which occurs through subtle changes in gene function, rather than bacteria acquiring resistance directly.

Although it is known that E. coli increases its chances of survival by adapting to its environment, the biological mechanisms that play a role in this process have not yet been fully understood.

The analysis also revealed that a protein called Rob plays a much more important role than expected in controlling entry and exit across the bacterial cell membrane. Caffeine triggers this gene regulator, leading to changes in a number of transporter proteins and reducing the entry of antibiotics into the cell.

NOT VALID FOR ALL BACTERIA

Scientists emphasize that this effect was observed in a laboratory environment, and it is not yet clear to what extent it applies to humans and how much coffee should be consumed.

Another interesting finding is that caffeine does not have this effect on Salmonella enterica, meaning it is not true for all bacterial species.

The researchers note that understanding these low-level resistance mechanisms is critical to improving the effectiveness of antibiotic treatment.

The study was published in the peer-reviewed scientific journal PLOS Biology.