Commercial Stevia does not inhibit growth or biofilm formation of Escherichia coli strain MG1655

Abstract

Stevia is a readily available, non-caloric sugar alternative with demonstrated non-carcinogenic and non-genotoxic activity. The sweetener is gaining worldwide popularity as a non-nutritive sweetener, with the global stevia market growing about 8% yearly since 2016. However, recent findings suggest that some non-stevia sweeteners may cause adverse health consequences by altering the gut microbiome’s composition and diversity, raising concern about stevia. Growth and adhesion are fundamental processes in the microbiome, and previous observations suggest that stevia may impact these processes. Therefore, we investigated the effects of commercial stevia on growth, adhesion, and biofilm formation of Escherichia coli MG1655. E. coli growth and biofilm formation were significantly inhibited when treated with 40% (v/v) stevia, compared to the untreated control. E. coli attachment was not significantly inhibited in any growth condition, despite inhibited biofilm formation. These findings suggest that relatively high concentrations of stevia affect E. coli surface-based biofilm formation, and planktonic growth.