Non-caloric artificial sweeteners exhibit antimicrobial activity against bacteria and promote bacterial evolution of antibiotic tolerance

• Published in: Journal of hazardous materials Vol. 433; p. 128840
• Main Authors: Yu, Zhigang, Guo, Jianhua
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.07.2022
• Subjects: Anti-Bacterial Agents - pharmacology; Antibiotic tolerance; Antimicrobial; Artificial sweeteners; Aspartame - pharmacology; Bacteria; Escherichia coli - genetics; Evolution; Reactive oxygen species; Saccharin - pharmacology; Sweetening Agents - pharmacology; Antimicrobial; Artificial sweeteners; Evolution; Reactive oxygen species; Antibiotic tolerance
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2022.128840

Non-caloric artificial sweeteners are being widely used as safe table sugar substitutes with highly intensive sweetness but low calories. Previous studies have suggested that some of the sweeteners can alter the gut microbiota composition and promote horizontal transfer of antibiotic resistance genes across bacterial genera. However, little is known about whether these sweeteners could show antibiotic-like antimicrobial activity against bacteria, especially gut relevant bacteria. Whether they could affect evolutional trajectory of antibiotic resistance or tolerance in bacteria is also not clear yet. Here we investigated four commonly used artificial sweeteners (saccharin, sucralose, aspartame, and acesulfame potassium) against both Gram-negative (Escherichia coli and Klebsiella pneumoniae) and positive (Bacillus subtilis) strains. Results show that all four sweeteners exhibit antimicrobial effects on these strains. The antimicrobial mechanism is due to increased reactive oxygen species (ROS) and cell envelope damage. Compared to sucrose and glucose, the treatment of artificial sweeteners stimulates bacterial efflux pumps and promotes bacterial evolution of antibiotic tolerance. Collectively, our finding provides insights into roles of artificial sweeteners in the emergence of antibiotic tolerance and calls for a re-evaluation of risks due to their intensive usage. [Display omitted] •Artificial sweeteners show antimicrobial activity against different bacterial cells.•Artificial sweeteners increase reactive oxygen species and damage cell envelope.•The tested sweeteners stimulate bacterial AcrAB-TolC efflux pump.•All the sweeteners accelerate bacterial evolution of antibiotic resistance.