Cambridge University study finds common sweeteners may disrupt gut bacteria

Researchers at Cambridge University examined the effects of 39 widely used sweeteners on 25 representative gut‑bacterial species. About three‑quarters of the sweeteners altered the growth of at least one bacterial strain. The strongest impact was observed when the stevia‑derived sweetener isosteviol was combined with the antidepressant duloxetine, which inhibited two key bacterial species and reduced overall microbial diversity in an artificial gut‑microbiome model. The combination also shifted the composition of the microbiome and affected cells linked to immune function.

Lead author Sonja Blasche said the findings challenge the view that sweeteners are metabolically neutral, especially when they are taken together with medicines or other additives. The study suggests that common sweeteners could directly influence gut health and may have broader implications for dietary recommendations and product formulation.