Caffeine Can Reduce Antibiotic Effectiveness in E.coli, Study Finds
A new study published in PLOS Biology reveals that caffeine can weaken teh effectiveness of certain antibiotics, specifically ciprofloxacin, against Escherichia coli (E. coli), a potential pathogen. researchers at the University of Tübingen’s Center for Microbial Functional Genomics (CMFI) discovered that caffeine triggers a series of events within the bacteria, ultimately reducing their uptake of the antibiotic.
The process begins wiht caffeine activating the gene regulator Rob, wich then alters several transport proteins in E. coli. “Caffeine triggers a cascade of events starting with the gene regulator Rob and culminating in the change of several transport proteins in E. coli – which in turn leads to a reduced uptake of antibiotics such as ciprofloxacin,” explains Ana Rita Brochado, a researcher involved in the study. This interaction is described as “antagonistic,” meaning caffeine opposes the antibiotic’s action.
Interestingly, this effect was not observed in Salmonella enterica, a closely related bacterial species. This suggests that even similar bacteria can respond differently to environmental factors like caffeine, likely due to variations in their transport pathways or how they utilize drugs. “Such fundamental research into the effect of substances consumed on a daily basis underscores the vital role of science in understanding and resolving real-world problems,” notes Prof. Dr.Dr. h.c. (Dōshisha) Karla Pollmann,President of the University of Tübingen.
The research contributes to the understanding of “low-level” antibiotic resistance – resistance that isn’t caused by traditional resistance genes, but by bacterial regulation and adaptation to their environment. The findings coudl influence future antibiotic treatment strategies, potentially impacting dosage, co-administered drugs, and dietary considerations.the study, titled “Systematic screen uncovers regulator contributions to chemical cues in Escherichia coli” by christoph Binsfeld, Roberto Olayo-Alarcon, Lucía Pérez Jiménez, Morgane Wartel, Mara stadler, André Mateus, Christian Müller and Ana Rita Brochado, was published on July 22, 2025. (DOI: 10.1371/journal.pbio.3003260).
