Non‑nutritive sweeteners linked to higher cardiometabolic risk and gut‑microbiome disruption

A systematic review of 21 randomized clinical trials found that non‑caloric sweeteners such as saccharin, aspartame, sucralose and stevia raise fasting insulin and HbA1c levels and may reduce insulin sensitivity compared with non‑caloric controls. Observational data also associate their consumption with an increased risk of type 2 diabetes and some cardiovascular outcomes, prompting clinicians to advise caution for patients with impaired glucose regulation.

A separate laboratory study from the University of Cambridge examined 39 sweeteners against 25 representative gut bacterial species. About one‑quarter of the sweeteners inhibited growth of at least one beneficial strain. When combined with common additives and drugs—including caffeine, vanillin and several antidepressants—the sweeteners produced more than 100 unexpected “cocktail” interactions, many of which amplified the negative impact on bacterial growth. The findings suggest that sweeteners can disturb the gut microbiome, especially in real‑world consumption scenarios.

Together, the evidence advises against routine substitution of sugar with non‑nutritive sweeteners for individuals at metabolic risk and highlights the need for further human studies on combined dietary and pharmaceutical exposures.