Supplements · Sweeteners · Gut & Microbiome
sucralose alters gut microbiome
Part of: • sucralose
📅 Last reviewed: 2026-07-15 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: Human trials (RCT / n-of-1)
How the studies fall
What the evidence shows
Sucralose does appear to shift the gut microbiome more consistently than aspartame: the Suez human RCT, a 10-week human study, and multiple reviews report dysbiosis, and it is one of the two sweeteners (with saccharin) that changed microbiota in clinical trials.
The evidence (11)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Ahmad et al. 2020 · Nutrients | RCT | contradicts | moderate | Realistic-dose double-blind crossover RCT: sucralose did NOT significantly change gut microbiota in healthy adults. |
| Morder et al. 2025 · Cancer Discov | animal | supports | moderate | Cancer Discovery: sucralose consumption disrupted the microbiome (mice), impairing cancer-immunotherapy response — a microbiome-mediated effect. |
| Kidangathazhe A et al 2025 · study_type: in-vitro | in-vitro | supports | medium | Minibioreactor arrays (human fecal inoculum), 35 days: sucralose significantly reduced microbial diversity, enriched Enterobacteriaceae, vs less-disruptive natural sweeteners. |
| Suez et al. 2022 · Cell | RCT | supports | high | Human RCT (Cell): sucralose altered gut-microbiome composition, with downstream glycemic effects in susceptible individuals. |
| Khattab 2026 · Curr Nutr Rep | observational | supports | low | Mechanistic review: sucralose modulates gut microbiota. |
| Gauthier et al. 2024 · Nutrition | observational | supports | moderate | Review of human trials: sucralose (with saccharin) was one of the sweeteners that significantly changed microbiota. |
| Conz et al. 2023 · Nutrients | observational | mixed | moderate | NNS-microbiota review: sucralose among sweeteners altering microbiota. |
| Mendez-Garcia et al. 2022 · Microorganisms | RCT | supports | low | 10-week sucralose in healthy adults: induced gut dysbiosis (shifts in Actinobacteria/Bacteroidetes/Firmicutes) and altered glucose/insulin. |
| Ruiz-Ojeda et al. 2019 · Adv Nutr | observational | supports | moderate | Adv Nutr review: sucralose is among the few sweeteners that measurably change human gut-microbiota composition. |
| Feng et al. 2024 · Metabolites | observational | supports | low | NAS-microbiome review: sucralose among perturbing agents. |
| Del Pozo et al. 2022 · Nutrients | observational | mixed | moderate | Review: current evidence indicates sucralose (and saccharin) can influence gut-microbiota composition. |
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