Why This Matters:
- Ace-K is one of the most widely used artificial sweeteners worldwide and is commonly found in beverages, dairy products, gum, and processed foods.
- Regulatory assessments have generally assumed that Ace-K is minimally metabolized by humans.
- If gut microbes can degrade Ace-K, the biological effects of this sweetener may be more complex than previously recognized.
- The findings raise questions about potential microbiome-mediated effects on intestinal health and risk assessment of non-nutritive sweeteners.
Key Findings: The authors used a dynamic in vitro gastrointestinal simulator inoculated with fecal microbiota from healthy children to evaluate the effects of acesulfame potassium (Ace-K) on the gut microbiome.¹
- Microbiome alterations: Ace-K exposure produced dose-dependent shifts in gut microbial communities, including increased abundance of Anaerostipes, Coprococcus, Subdoligranulum, Blautia, Alistipes, Bacteroides thetaiotaomicron, and Sutterella wadsworthensis.
- Evidence of Ace-K metabolism: Metagenomic analyses identified increased abundance of microbial enzymes with sulfatase and amidase activity, suggesting potential pathways for Ace-K degradation. Ace-K supplementation was also associated with increased butyrate production, indicating altered microbial metabolic activity.
- Intestinal barrier effects: Exposure of Caco-2 intestinal epithelial cells to microbiota-conditioned media derived from Ace-K-treated cultures was associated with impaired epithelial barrier integrity, suggesting that microbial metabolism of Ace-K may influence intestinal barrier function.
Bigger Picture: This study challenges the long-standing assumption that acesulfame potassium (Ace-K) is biologically inert in the gastrointestinal tract by providing evidence that the gut microbiome may metabolize it and that this interaction can measurably alter microbial composition and function in vitro. While the work does not demonstrate clinical effects in humans, it raises the possibility that non-nutritive sweeteners may exert biologically relevant effects indirectly through microbiome-mediated metabolism rather than direct host absorption.
(Image Credit: iStock/nopparit)
References:
1. Bellanco et al. 2026. Human Gut Microbiome Can Degrade the Sweetener Acesulfame K with Potential Damaging Effects in the Intestinal Barrier Function. Journal of Agricultural and Food Chemistry.
