On Sept. 10, 2025, a federal judge blocked the Department of Justice’s attempt to subpoena medical records[1] and other private health information on minors receiving hormone therapy and other gender affirming care at Boston Children’s Hospital.
Researchers have discovered that everyday substances like caffeine can influence how bacteria such as E. coli respond to antibiotics. By examining 94 common drugs and food ingredients, scientists found that certain compounds trigger genetic regulators that control bacterial transport proteins, altering what gets inside the cells. In the case of caffeine, this led to reduced uptake of the antibiotic ciprofloxacin, weakening its effectiveness.
FULL STORY
Caffeine may secretly help bacteria resist antibiotics. Credit: Shutterstock
Ingredients of our daily diet - including caffeine - can influence the resistance of bacteria to antibiotics. This has been shown in a new study by a team of researchers at the Universities of Tübingen and Würzburg led by Professor Ana Rita Brochado. They discovered bacteria such as Escherichia coli (E. coli) orchestrate complex regulatory cascades to react to chemical stimuli from their direct environment which can influence the effectiveness of antimicrobial drugs.
In a systematic screening, Brochado's team investigated how 94 different substances - including antibiotics, prescription drugs, and food ingredients - influence the expression of key gene regulators and transport proteins of the bacterium E. coli, a potential pathogen. Transport proteins function as pores and pumps in the bacterial envelope and control which substances enter or leave the cell. A finely tuned balance of these mechanisms is crucial for the survival of bacteria.
Researchers describe phenomenon as an 'antagonistic interaction'
"Our data show that several substances can subtly but systematically influence gene regulation in bacteria," says PhD student Christoph Binsfeld, first author of the study. The findings suggest even everyday substances without a direct antimicrobial effect - e.g. caffeinated drinks - can impact certain gene regulators that control transport proteins, thereby changing what enters and leaves the bacterium. "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. This results in caffeine weakening the effect of this antibiotic. The researchers describe this phenomenon as an 'antagonistic interaction.'
"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." Ana Rita Brochado
This weakening effect of certain antibiotics was not detectable in Salmonella enterica, a pathogen closely related to E. coli. This shows that even in similar bacterial species, the same environmental stimuli can lead to different reactions - possibly due to differences in transport pathways or their contribution to antibiotic uptake. President Prof. Dr. Dr. h.c. (Dōshisha) Karla Pollmann emphasizes: "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."
The study, which has been published in the scientific journal PLOS Biology, makes an important contribution to the understanding of what is called 'low-level' antibiotic resistance, which is not due to classic resistance genes, but to regulation and environmental adaptation. This could have implications for future therapeutic approaches, including what is taken during treatment and in what amount, and whether another drug or food ingredient - should be given greater consideration.
Story Source:
Materials[1] provided by University of Tübingen. Note: Content may be edited for style and length.
Journal Reference:
Christoph Binsfeld, Roberto Olayo-Alarcon, Lucía Pérez Jiménez, Morgane Wartel, Mara Stadler, André Mateus, Christian Müller, Ana Rita Brochado. Systematic screen uncovers regulator contributions to chemical cues in Escherichia coli. PLOS Biology, 2025; 23 (7): e3003260 DOI: 10.1371/journal.pbio.3003260[2]
Cite This Page:
University of Tübingen. "Your morning coffee could secretly be weakening antibiotics." ScienceDaily. ScienceDaily, 11 September 2025. <www.sciencedaily.com/releases/2025/09/250911080113.htm>.
University of Tübingen. (2025, September 11). Your morning coffee could secretly be weakening antibiotics. ScienceDaily. Retrieved September 11, 2025 from www.sciencedaily.com/releases/2025/09/250911080113.htm
University of Tübingen. "Your morning coffee could secretly be weakening antibiotics." ScienceDaily. www.sciencedaily.com/releases/2025/09/250911080113.htm (accessed September 11, 2025).
June 9, 2025 A new Rutgers Health study reveals a surprising twist in the antibiotic resistance story: instead of simply killing bacteria, drugs like ciprofloxacin can actually trigger a kind of microbial ...
Apr. 16, 2024 Researchers have identified the types of E.coli responsible for neonatal meningitis -- around 50 per cent of infections are caused by two types of E. coli. The study was the largest to date, ...
Nov. 21, 2023 Scientists have discovered that bacteria can create something like memories about when to form strategies that can cause dangerous infections in people, such as resistance to antibiotics and ...
Aug. 28, 2023 After a nearly threefold drop in prescriptions for the antibiotic ciprofloxacin between 2015 and 2021, the rates of ciprofloxacin-resistant E. coli bacteria circulating in the community did not ...
July 18, 2023 To understand the main determinants behind worldwide antibiotic resistance dynamics, scientists developed a statistical model based on a large-scale spatial-temporal analysis. Using the ATLAS ...
Oct. 1, 2020 Researchers investigated the effects of adipose-derived stem cells (ADSCs) loaded with the antibiotic ciprofloxacin on osteomyelitis caused by implants. By administering ADSC-loaded ciprofloxacin to ...
In October 2023, an unthinkable tragedy unfolded in Coleman, Wisconsin: An 8‑month‑old girl lost her life when a driver, impaired by cannabis, ran a stop sign and crashed into another vehicle. In February 2025, the driver pleaded guilty to negligent vehicular homicide[1] and drugged driving with a minor passenger – and now faces up to 10 years behind bars.
These preventable circumstances highlight a stark reality: Drugged...
