AUTHOR=Shil Aparna , Ladeira Faria Luisa Maria , Walker Caray Anne , Chichger Havovi 

TITLE=The artificial sweetener neotame negatively regulates the intestinal epithelium directly through T1R3-signaling and indirectly through pathogenic changes to model gut bacteria

JOURNAL=Frontiers in Nutrition

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2024.1366409

DOI=10.3389/fnut.2024.1366409

ISSN=2296-861X

ABSTRACT=<sec><title>Introduction</title><p>Recent studies have indicated considerable health risks associated with the consumption of artificial sweeteners. Neotame is a relatively new sweetener in the global market however there is still limited data on the impact of neotame on the intestinal epithelium or the commensal microbiota.</p></sec><sec><title>Methods</title><p>In the present study, we use a model of the intestinal epithelium (Caco-2) and microbiota (<italic>Escherichia coli</italic> and <italic>Enterococcus faecalis</italic>) to investigate how physiologically-relevant exposure of neotame impacts intestinal epithelial cell function, gut bacterial metabolism and pathogenicity, and gut epithelium-microbiota interactions.</p></sec><sec><title>Results</title><p>Our findings show that neotame causes intestinal epithelial cell apoptosis and death with siRNA knockdown of T1R3 expression significantly attenuating the neotame-induced loss to cell viability. Similarly, neotame exposure results in barrier disruption with enhanced monolayer leak and reduced claudin-3 cell surface expression through a T1R3-dependent pathway. Using the gut bacteria models, <italic>E. coli</italic> and <italic>E. faecalis</italic>, neotame significantly increased biofilm formation and metabolites of <italic>E. coli</italic>, but not <italic>E. faecalis</italic>, reduced Caco-2 cell viability. In co-culture studies, neotame exposure increased adhesion capacity of <italic>E. coli</italic> and <italic>E. faecalis</italic> onto Caco-2 cells and invasion capacity of <italic>E. coli</italic>. Neotame-induced biofilm formation, <italic>E.coli</italic>-specific Caco-2 cell death, adhesion and invasion was identified to be meditated through a taste-dependent pathway.</p></sec><sec><title>Discussion</title><p>Our study identifies novel pathogenic effects of neotame on the intestinal epithelium or bacteria alone, and in co-cultures to mimic the gut microbiome. These findings demonstrate the need to better understand food additives common in the global market and the molecular mechanisms underlying potential negative health impacts.</p></sec>