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 SY, Friel J, Mackay D 2020 · Nutrients | RCT | contradicts | moderate | Realistic-dose double-blind crossover RCT: sucralose did NOT significantly change gut microbiota in healthy adults. |
| Morder KM, Nguyen M, Wilfahrt DN, Dahmani ZL, Burr ABP, Xie B, Morikone M, Nieves-Rosado H, Gunn WG, Hurd DE, Wang H, Mullett SJ, Bossong K, Gelhaus SL, Rajasundaram D, Kane LP, Delgoffe GM, Das J, Davar D, Overacre-Delgoffe AE 2025 · Cancer Discov | animal | supports | moderate | Cancer Discovery: sucralose consumption disrupted the microbiome (mice), impairing cancer-immunotherapy response — a microbiome-mediated effect. |
| Kidangathazhe A, Amponsah T, Maji A, Adams S, Chettoor M, Wang X, Scaria J 2025 · Frontiers in Microbiology | in-vitro | supports | low | Ex-vivo minibioreactor arrays inoculated with faecal microbiota from 3 healthy donors, 35 days (sucralose 96.88 mg/L on days 7-21): 'sucralose led to a much larger and more significant reduction in diversity' and was 'the most divergent from the control', enriching Veillonellaceae, Bifidobacteriaceae and Enterobacteriaceae; network became control-like after withdrawal. Quality low: 3 donors ('our results are based on testing fecal microbiota samples from a small number of donors'), descriptive analysis with no test statistics reported, in-vitro. |
| Suez et al. 2022 · Cell | RCT | supports | high | Human RCT (Cell): sucralose altered gut-microbiome composition, with downstream glycemic effects in susceptible individuals. |
| Khattab R 2026 · Curr Nutr Rep | observational | supports | low | Mechanistic review: sucralose modulates gut microbiota. |
| Gauthier E, Milagro FI, Navas-Carretero S 2024 · Nutrition | observational | supports | moderate | Review of human trials: sucralose (with saccharin) was one of the sweeteners that significantly changed microbiota. |
| Conz A, Salmona M, Diomede L 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 FJ, Plaza-Díaz J, Sáez-Lara MJ, Gil A 2019 · Adv Nutr | observational | supports | moderate | Adv Nutr review: sucralose is among the few sweeteners that measurably change human gut-microbiota composition. |
| Feng J, Peng J, Hsiao YC, Liu CW, Yang Y, Zhao H, Teitelbaum T, Wang X, Lu K 2024 · Metabolites | observational | supports | low | NAS-microbiome review: sucralose among perturbing agents. |
| Del Pozo S, Gómez-Martínez S, Díaz LE, Nova E, Urrialde R, Marcos A 2022 · Nutrients | observational | mixed | moderate | Review: current evidence indicates sucralose (and saccharin) can influence gut-microbiota composition. |
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