Artificial sweeteners disturb the beneficial gut bacteria and thereby induce glucose intolerance in animals and humans.
Original statement
ومحلِّيات صناعية تُخل بالبكتيريا النافعة ... والسبب جزئياً أن المحلِّيات الصناعية — كما أوضحت دراسة Nature عام 2014 — تُحدث خللاً في بكتيريا الأمعاء يقود إلى عدم تحمُّل الجلوكوز.
verbatim according to source. Translation by the project; the Arabic wording is authoritative.
Translation
Artificial sweeteners disturb the beneficial gut bacteria and thereby induce glucose intolerance in animals and humans.
Origin
- Source status
- Archive editors
- Attribution
- Archive editors (study selection and narrative are the archive's, not necessarily Elawady's)
- Origin
- https://eltayebat.com/rule/soda/
- Attribution uncertainty
- The archive homepage states that the forbidden-food section is supported by research 'independently of Dr. Diaa's words'. No evidence was found that Elawady himself cited these studies.
- Claimed mechanism
Microbiome alteration.
- Claimed health effect
Glucose intolerance.
- Population concerned
General population
- Geographic restriction by Elawady
none found
Scientific assessment
Potentially true – Some evidence points in favour of the statement, but it is not sufficient for a clear judgement.
Certainty of evidence: low – Further research is likely to change the assessment considerably.
1. What was claimed?
Sweeteners damage gut bacteria and cause glucose intolerance.
2. What is demonstrably correct?
Suez 2014 (A-SOD-09) showed microbiome-dependent glucose intolerance in mice and reported similar effects in healthy humans; Suez 2022 RCT (I-SOD-03) found saccharin and sucralose impaired glycaemic responses and each sweetener altered the microbiome.
3. What is wrong or exaggerated?
Not all sweeteners behaved the same: in 2022, aspartame and stevia did not significantly impair glycaemic responses. Effects were person-specific and short-term. The 2014 human data were a small add-on to mouse work.
4. What remains unclear?
Long-term clinical consequences (e.g., diabetes incidence) are not established.
5. Which studies support it?
6. Which studies contradict it?
I-SOD-106 (saccharin RCT: no microbiome or glucose effect), I-SOD-107 (sucralose RCT meta-analysis: no significant effect), I-SOD-03 (no significant glycaemic effect for aspartame and stevia).
7. What applies to Germany and Europe?
Sweeteners are authorised in the EU under Reg. (EC) 1333/2008 with ADIs; WHO 2023 advises against NSS use for weight control (conditional).
8. What is known about Egypt?
No Egypt-specific data.
9. What practical conclusion is appropriate?
Evidence supports caution and further research rather than certainty of harm.
Assessment details
- Rationale for certainty of evidence
Mouse experiments with faecal transfer and a small human component (2014) and a 120-person RCT (2022) showing that saccharin and sucralose, but not aspartame or stevia, impaired glycaemic responses in a person-specific way over 2 weeks. Other randomised evidence is null: a double-blind RCT of saccharin at the maximum acceptable daily intake found no microbiome or glucose-tolerance changes (I-SOD-106), and a 2026 meta-analysis of 10 sucralose RCTs found no significant effects on microbial diversity, fasting glucose or insulin resistance (I-SOD-107). Clinical relevance and long-term effects are unknown.
- Source quality
Archive accurately summarises the 2014 abstract but generalises to all sweeteners and to humans 'alike'.
- Regional transferability
High (mechanism not region-specific).
- Individual exceptions
Effects appear person-specific; not all people respond.
- Regional scope of the claim
- general (biological/medical)
- Last reviewed
- 26 October 2026 provisional
Scientific evidence in detail
Overinterpreted – A real finding exists, but the claim draws more from it than the data allow (e.g. association taken as cause, animal data applied to humans, small effect presented as large).
Research question: Do artificial sweeteners disturb gut bacteria and thereby cause glucose intolerance in humans?
Research question in detail (PICO)
- Population
- Healthy adults; mice
- Intervention or exposure
- Non-nutritive sweeteners (saccharin, sucralose, aspartame, stevia)
- Comparison
- Placebo/glucose control
- Geographic scope
- universal
- Outcomes
- Microbiome composition
- Glucose tolerance
Study results as reported by the authors. Our assessment follows below.
What speaks for the claim?
Sweeteners and blood sugar: a 120-person trial
Suez J et al.. Cell 2022 · PMID 35987213 · DOI 10.1016/j.cell.2022.07.016 Randomised controlled trialabstract checkedSuez 2022 RCT (120 adults): saccharin and sucralose impaired glycaemic responses in a person-specific, microbiome-linked way over 2 weeks.
- Actual result
- Saccharin and sucralose impaired glycaemic responses; aspartame and stevia did not.
- Methodological quality
- high (RCT)
- Relevance
- direct
- Limitations
- Short; person-specific.
Sweeteners, gut bacteria and blood sugar
Suez 2014: microbiome-dependent glucose intolerance in mice, transferable by faecal transplant.
- Actual result
- Mouse data plus small human component.
- Methodological quality
- moderate
- Relevance
- indirect (mainly animal)
- Limitations
- Animal model.
What speaks against the claim?
High-dose saccharin did not change gut bacteria or blood sugar
Serrano J et al.. Microbiome 2021 · PMID 33431052 · DOI 10.1186/s40168-020-00976-w Randomised controlled trialabstract checkednewly addedDouble-blind RCT: saccharin at maximum ADI for 2 weeks did not change microbiome or glucose tolerance.
- Actual result
- No OGTT or microbiome changes.
- Methodological quality
- high (RCT)
- Relevance
- direct
- Limitations
- Short; capsules.
Sucralose trials show no clear gut or blood-sugar effect
Wulandari DT et al.. Int J Mol Sci 2026 · PMID 42794802 · DOI 10.3390/ijms27188377 Meta-analysisabstract checkednewly added2026 meta-analysis of 10 RCTs: sucralose did not significantly alter diversity, fasting glucose or HOMA-IR.
- Actual result
- Shannon SMD -0.00; FBG SMD -0.04.
- Methodological quality
- moderate
- Relevance
- direct
- Limitations
- Small imprecise trials.
What does the overall evidence say?
Editorial assessment based on the studies above – not itself a study result.
Which position is better supported?
Animal effects are established; human randomised evidence is inconsistent: one RCT found person-specific glycaemic effects of saccharin and sucralose, others found none.
Why some studies weigh more
Human RCTs weigh more than mouse work; they conflict.
Is a causal relationship established? Possible, not established Mechanism plausible in mice; human relevance unclear.
Remaining uncertainty
Long-term clinical consequences.
Justified conclusion
Partly supported; overstated as a general rule.
Why do studies seem to disagree?
Suez 2022 vs Serrano 2021: sachets in water vs capsules, different baseline microbiomes, person-specific responders; both short-term.
Does this depend on the country?
- General biological effects
- Universal.
- Legal rules
- EU-authorised sweeteners with ADIs.
A regional difference that changes the conclusion is not supported by robust data.
Certainty of the overall evidence (GRADE, simplified)
- Main outcome
- Glucose tolerance with NNS in humans
- Starting level
- high (randomised trials)
- Reasons for downgrading
- inconsistency
- imprecision
- indirectness (short-term surrogate)
- Result
- low
Simplified assessment by a single reviewer, following the GRADE approach; not a formal GRADE panel. GRADE rates the body of evidence for one outcome, not individual studies.
Clinical guidelines and official statements checked
- WHO: Use of non-sugar sweeteners: WHO guideline (2023), publication page (I-SOD-08) (2023) · Original publication
Guidance on NSS use to reduce unhealthy weight gain and NCD risk; not based on toxicological safety assessment and not intended to replace JECFA acceptable daily intakes; accompanying news release: recommends against NSS for weight control (conditional). - ADA: 5. Facilitating Positive Health Behaviors and Well-being to Improve Health Outcomes: Standards of Care in Diabetes-2026 (Diabetes Care 2026;49 Suppl 1:S89-S131; I-INTC-03) (2026) · Original publication
Rec. 5.14: minimise sugar-sweetened beverages, sweets, refined grains, processed and ultra-processed foods. Rec. 5.21: encourage water over other beverages (A). Rec. 5.22: nonnutritive sweeteners can replace sugar-sweetened products if consumed in moderation and for the short term (B). Rec. 5.25: replace sugar-sweetened beverages (including any juices) with water or low/no-calorie beverages and minimise foods with added sugar (B).
Search strategy
Documented literature searches for this review (search strings in the original database syntax).
| Database | Date | Search | Looking for | Hits | Included |
|---|---|---|---|---|---|
| Europe PMC | 26 October 2026 | (saccharin OR sucralose OR aspartame OR "non-nutritive sweetener" OR "artificial sweetener") AND ("gut microbiota" OR microbiome) AND ("glucose tolerance" OR "glucose intolerance" OR "insulin sensitivity") AND (randomized OR randomised) AND (human OR healthy OR adults) | both directions | 523 | |
| Europe PMC | 26 October 2026 | (TITLE:"non-nutritive sweeteners" OR TITLE:"artificial sweeteners" OR TITLE:"low-calorie sweeteners") AND (glycemic OR glycaemic OR "glucose") AND ("meta-analysis") AND (randomized) | both directions | 45 | |
| PubMed | 26 October 2026 | Serrano J[au] AND saccharin AND microbiota | contradicting evidence | 1 |
Open questions
Long-term trials with clinical outcomes; responder characteristics.
How deeply was this checked?
5 linked studies: 0 checked in full text (0 of them with a structured risk-of-bias assessment), 5 on the basis of the abstract, 0 bibliographically only. No formal assessment with two independent reviewers and no independent human expert review has taken place yet.
Last scientific review: 26 October 2026
History of the verdict
- 25 October 2026 · Phase 1 · Initial assessment: Potentially true (low)
- 26 October 2026 · Phase 4 (systematic evidence review) · Re-examined with extended evidence; verdict unchanged: Potentially true (low)
Contradicting RCTs show inconsistency but do not refute the person-specific findings; verdict unchanged, wording sharpened.
New sources: I-SOD-106 I-SOD-107
In plain language
Experiments in mice and a small group of people suggested that some sweeteners change gut bacteria and blood sugar control. A 2022 trial found such changes for saccharin and sucralose in some people, but not for aspartame or stevia. Other trials, including one with high-dose saccharin and a summary of ten sucralose trials, found no changes. Whether sweeteners cause disease in the long run is not known.
Studies on this claim
Studies supporting the claim (2)
-
Sweeteners, gut bacteria and blood sugar
Suez J et al.. Nature 2014 · PMID 25231862 · DOI 10.1038/nature13793Animal studycited by the Tayebat archiveabstract checked★ key studyIn mice, sweeteners changed gut bacteria and caused glucose intolerance; a small human test showed similar effects.
Does the study support the specific claim? Partly · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Do non-caloric artificial sweeteners alter glucose tolerance via the microbiota?
- How was the study done?
Mouse experiments (antibiotics, faecal transplants into germ-free mice) plus human observational/intervention data.
- How many people, animals or samples were studied?
Not stated in abstract; Mice; healthy human subjects
- What was actually found?
NAS induced glucose intolerance via microbiota; abrogated by antibiotics; transferable via faecal transplant; similar dysbiosis and glucose intolerance demonstrated in healthy human subjects.
- How large was the observed effect?
Not applicable
- What do the results mean in everyday life?
Some sweeteners may affect blood sugar via gut bacteria.
- What are the study's limitations?
Human data small (size not in abstract); Commercial formulations contained glucose fillers (not in abstract); Short-term
- What does it say about Elawady's specific claim?
Mechanistic support for C-SOD-07.
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
That diet soda causes diabetes, stroke or dementia.
-
Sweeteners and gut bacteria (duplicate)
Suez J et al.. Nature 2014 · PMID 25231862 · DOI 10.1038/nature13793Animal studycited by the Tayebat archiveabstract checkedSame paper as A-SOD-09.
Does the study support the specific claim? Partly · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
See A-SOD-09.
- How was the study done?
Same publication as A-SOD-09 (listed twice by the archive).
- How many people, animals or samples were studied?
Not stated in abstract; Mice; healthy humans
- What was actually found?
See A-SOD-09.
- How large was the observed effect?
Not applicable
- What do the results mean in everyday life?
See A-SOD-09.
- What are the study's limitations?
Duplicate of A-SOD-09
- What does it say about Elawady's specific claim?
Supports C-SOD-07 (duplicate).
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
See A-SOD-09.
No study in this group is marked as key.
Studies contradicting or limiting the claim (2)
-
High-dose saccharin did not change gut bacteria or blood sugar
Serrano J et al.. Microbiome 2021 · PMID 33431052 · DOI 10.1186/s40168-020-00976-wRandomised controlled trialindependent cross-checkabstract checked★ key studyIn a placebo-controlled trial, two weeks of saccharin at the maximum acceptable dose changed neither gut bacteria nor glucose tolerance.
Saccharin at max ADI: no microbiome or glucose effect.
Does the study support the specific claim? No · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Test whether saccharin harms gut bacteria and glucose control.
- How was the study done?
Double-blind randomised trial in humans plus mouse experiments.
- How many people, animals or samples were studied?
Healthy adults; mice.
- What was actually found?
No changes in gut bacteria or glucose tolerance.
- How large was the observed effect?
No significant differences.
- What do the results mean in everyday life?
Effects seen in mice in 2014 were not confirmed for saccharin in this trial.
- What are the study's limitations?
Short trial; capsules.
- What does it say about Elawady's specific claim?
Contradicts the claim for saccharin.
- Do the results apply to Germany and Europe?
Applicable.
- What can explicitly not be concluded from this study?
Cannot rule out effects in some individuals or over years.
-
Sucralose trials show no clear gut or blood-sugar effect
Wulandari DT et al.. Int J Mol Sci 2026 · PMID 42794802 · DOI 10.3390/ijms27188377Meta-analysisindependent cross-checkabstract checkedA 2026 meta-analysis of 10 small trials found no significant effect of sucralose on gut bacteria diversity, fasting glucose or insulin resistance.
No significant pooled effect of sucralose on microbiota diversity or fasting glucose.
Does the study support the specific claim? No · Methodological quality: moderate · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Pool trials on sucralose and gut bacteria.
- How was the study done?
Meta-analysis of randomised trials.
- How many people, animals or samples were studied?
Ten small trials.
- What was actually found?
No significant changes in diversity or blood sugar.
- How large was the observed effect?
Shannon SMD -0.00; fasting glucose SMD -0.04.
- What do the results mean in everyday life?
Short-term sucralose use did not clearly disturb gut bacteria.
- What are the study's limitations?
Small, short, imprecise trials.
- What does it say about Elawady's specific claim?
Limits the claim.
- Do the results apply to Germany and Europe?
Applicable.
- What can explicitly not be concluded from this study?
Cannot exclude long-term or individual effects.
No study in this group is marked as key.
Studies with mixed or unclear results (1)
-
Sweeteners and blood sugar: a 120-person trial
Suez J et al.. Cell 2022 · PMID 35987213 · DOI 10.1016/j.cell.2022.07.016Randomised controlled trialindependent cross-checkabstract checked★ key studySaccharin and sucralose worsened glucose responses in some people; aspartame and stevia did not significantly.
Does the study support the specific claim? Partly · Methodological quality: high · Certainty of evidence: see overall assessment of the claim
Original publication · Scientific details
Study explained simply
- What did the researchers want to find out?
Do NNS causally affect human microbiome and glycaemic responses?
- How was the study done?
Randomized controlled trial (2 weeks) plus gnotobiotic mouse transfer.
- How many people, animals or samples were studied?
120; Healthy adults
- What was actually found?
Each NNS distinctly altered stool and oral microbiome and plasma metabolome; saccharin and sucralose significantly impaired glycaemic responses; responder-specific effects reproduced in mice.
- How large was the observed effect?
Qualitative (numbers not in abstract)
- What do the results mean in everyday life?
Some sweeteners affect some people.
- What are the study's limitations?
Short (2 weeks); Clinical relevance unknown; Authors' commercial interests
- What does it say about Elawady's specific claim?
Mixed for C-SOD-07.
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
Long-term disease risk.
No study in this group is marked as key.
Regional context
Germany / EU
Sweeteners are authorised in the EU under Reg. (EC) 1333/2008 with ADIs; WHO 2023 advises against NSS use for weight control (conditional).
Egypt
No Egypt-specific data.
What applies in my country?
General scientific assessment
Potentially true Some sweeteners altered gut bacteria and glucose responses in mice and in some people in one trial, but other trials found no effect; long-term harm is unproven.
The following areas of food safety are relevant to this statement:
- Additives and processing
- Controls, imports, recalls, labelling
Honey, sugar, sweets
Choose a country to see the checked information for it.
Limits: legal rules describe what is allowed, not what every single food contains. Measurement data come from samples and are meaningful only together with their method details.
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References
- Artificial sweeteners induce glucose intolerance by altering the gut microbiota.. Suez J et al.. Nature 2014 · PMID 25231862 · DOI 10.1038/nature13793
- Artificial sweeteners induce glucose intolerance by altering the gut microbiota.. Suez J et al.. Nature 2014 · PMID 25231862 · DOI 10.1038/nature13793
- High-dose saccharin supplementation does not induce gut microbiota changes or glucose intolerance in healthy humans and mice.. Serrano J et al.. Microbiome 2021 · PMID 33431052 · DOI 10.1186/s40168-020-00976-w
- Effect of Sucralose Consumption on Gut Microbiota: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.. Wulandari DT et al.. Int J Mol Sci 2026 · PMID 42794802 · DOI 10.3390/ijms27188377
- Personalized microbiome-driven effects of non-nutritive sweeteners on human glucose tolerance.. Suez J et al.. Cell 2022 · PMID 35987213 · DOI 10.1016/j.cell.2022.07.016