Researchers from the University of Tübingen and Würzburg have found that components of our everyday diet, including caffeine, can influence bacterial resistance to antibiotics. They observed that E. coli bacteria adjust complex modulation cascades to respond to chemical signals from their immediate environment, potentially impacting the effectiveness of antibiotics.
This diagram illustrates a 3D computer-generated image of a group of E. coli. Image credits: James Archer, CDC.
In a systematic screening, Professor Ana Rita Brochado and her team examined the effects of 94 different substances, including antibiotics, prescription medications, and dietary components, on the expression of critical gene regulators and transport proteins in E. coli bacteria.
Transport proteins function as pores and pumps within bacterial membranes, regulating the movement of substances in and out of cells.
A precisely adjusted balance of these mechanisms is crucial for bacterial survival.
“Our data reveals that certain substances can exert subtle yet systematic influences on gene regulation in bacteria,” explained doctoral student Christoph Vincefeld.
“These findings indicate that even everyday substances, which lack direct antibacterial properties, like caffeinated beverages, can impact specific gene regulators that modulate transport proteins, thereby modifying bacterial import and composition.”
“Caffeine initiates a cascade of events starting with the lob gene regulator, resulting in alterations in several transport proteins in E. coli. This effect reduces the uptake of antibiotics such as ciprofloxacin,” Professor Rita Brochado added.
“Consequently, this diminishes the antibiotic’s effectiveness.”
The researchers characterize this effect as an “antagonistic interaction.”
The diminishing efficacy of certain antibiotics also applies to salmonella enterica, a close relative of E. coli.
This suggests that even similar bacterial species can react differently to identical environmental cues, likely due to variations in transport pathways and how they contribute to antibiotic absorption.
“This foundational study on the effects of commonly consumed substances highlights the significant role of science in addressing and resolving real-world challenges,” stated Professor (Doshisha) Karla Pollmann.
“This research contributes meaningfully to the understanding of what is termed ‘low-level’ antibiotic resistance, which does not result from classical resistance genes but rather through regulation and environmental adaptation.”
“These insights could influence future treatment strategies involving drug or dietary component modifications.”
The results will be published online in PLOS Biology.
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C. Vincefeld et al. 2025. Systematic screens reveal regulatory contributions to chemical cues in E. coli. Plos Biol 23(7): E3003260; doi: 10.1371/journal.pbio.3003260
Source: www.sci.news
