Antibiotic exposure increases the risk of new-onset Crohn's disease (inflammatory bowel disease), nearly doubling it in children.
Original statement
ربط تحليل Ungaro عام 2014 المضادات بمضاعفة خطر مرض كرون لدى الأطفال
verbatim according to source. Translation by the project; the Arabic wording is authoritative.
Translation
Antibiotic exposure increases the risk of new-onset Crohn's disease (inflammatory bowel disease), nearly doubling it in children.
Origin
- Source status
- Archive editors
- Attribution
- Archive editors (eltayebat.com)
- Origin
- https://eltayebat.com/rule/antibiotic-overuse/
- Attribution uncertainty
- Archive editorial narrative and featured-study cards, written by the archive operators; study selection is the archive's, not necessarily Elawady's.
- Claimed mechanism
Microbiome disruption.
- Claimed health effect
Crohn's disease/IBD.
- Population concerned
Children and adults
- 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?
Antibiotics raise Crohn's/IBD risk.
2. What is demonstrably correct?
Ungaro meta-analysis: CD OR 1.74 (1.35-2.23); children OR 2.75 (1.72-4.38); UC not significant (A-ABX-07). UK children: anti-anaerobic antibiotics associated with IBD, aHR 5.51 before age 1 (A-ABX-08). Sweden (adults): ever vs never aOR 1.94 (1.85-2.03); sibling comparison aOR 1.35 (1.28-1.43) for 3+ dispensations (I-ABX-06). 2026 meta-analysis of childhood exposure: IBD RR 1.42 (1.23-1.66), CD RR 1.59 (1.39-1.81), not attenuated by adjustment for infections (I-ABX-118). Scandinavian birth cohorts: first-year antibiotics aHR 1.33 (1.01-1.76) after adjustment for infection frequency (I-ABX-119).
3. What is wrong or exaggerated?
'Nearly doubling in children' rests on the older Ungaro subgroup (OR 2.75, few studies); the most recent pooled estimate for childhood exposure is RR 1.59 for Crohn's disease (I-ABX-118), i.e. about 60% higher relative risk, not a doubling. It is association, not proven causation; within families the excess odds were about 35% (I-ABX-06).
4. What remains unclear?
Causal mechanism in humans; magnitude of residual confounding.
5. Which studies support it?
A-ABX-07, A-ABX-08, I-ABX-06, I-ABX-118, I-ABX-119.
6. Which studies contradict it?
Partly limiting: weaker association within siblings (aOR 1.35; I-ABX-06) and a smaller pooled childhood estimate (CD RR 1.59; I-ABX-118) than the 'near-doubling'; reverse causation cannot be fully excluded.
7. What applies to Germany and Europe?
Swedish data are EU-relevant (I-ABX-06).
8. What is known about Egypt?
No Egyptian data were reviewed.
9. What practical conclusion is appropriate?
One more reason for stewardship; not a reason to withhold necessary antibiotics.
Assessment details
- Rationale for certainty of evidence
Consistent observational associations with dose-response; a large Swedish study of adults found the association attenuated but persisting with sibling controls (aOR 1.35 for 3+ dispensations). The 'children' element rests on the Ungaro meta-analysis subgroup (OR 2.75) and a UK paediatric cohort. Reverse causation (early IBD symptoms treated with antibiotics) and confounding cannot be excluded.
- Source quality
Meta-analysis of observational studies plus large cohorts.
- Regional transferability
Moderate.
- 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: Does antibiotic exposure increase the risk of new-onset Crohn's disease, and does it nearly double it in children?
Research question in detail (PECO)
- Population
- Children and adults
- Intervention or exposure
- Antibiotic exposure
- Comparison
- No exposure; siblings
- Geographic scope
- Universal biology
- Outcomes
- Crohn's disease
- IBD
Study results as reported by the authors. Our assessment follows below.
What speaks for the claim?
Childhood antibiotics linked to later Crohn's disease
Størdal K et al.. Inflamm Bowel Dis 2026 · PMID 41617205 · DOI 10.1093/ibd/izaf324 Meta-analysisabstract checkednewly added2026 meta-analysis of childhood exposure.
- Actual result
- CD RR 1.59 (1.39-1.81); IBD RR 1.42 (1.23-1.66); adjustment for infections did not attenuate.
- Methodological quality
- moderate
- Relevance
- direct
- Limitations
- Observational.
Infant antibiotics linked to later IBD, not explained by infections
Mårild K et al.. Aliment Pharmacol Ther 2025 · PMID 39450871 · DOI 10.1111/apt.18358 Cohort studyabstract checkednewly addedTwo Scandinavian birth cohorts.
- Actual result
- aHR 1.33 (1.01-1.76) adjusted for infection frequency.
- Methodological quality
- moderate
- Relevance
- direct
- Limitations
- Few cases.
Antibiotics and IBD in adults (Sweden)
Nguyen LH et al.. Lancet Gastroenterol Hepatol 2020 · PMID 32818437 · DOI 10.1016/S2468-1253(20)30267-3 Case-control studyfull text, structured risk-of-bias assessmentSwedish national case-control with sibling comparison (adults).
- Actual result
- Sibling aOR 1.35 (1.28-1.43) for 3+ dispensations.
- Methodological quality
- high
- Relevance
- direct (adults)
What speaks against the claim?
Antibiotics and Crohn's disease (meta-analysis)
Ungaro R et al.. Am J Gastroenterol 2014 · PMID 25223575 · DOI 10.1038/ajg.2014.246 Meta-analysisabstract checkedUngaro 2014 meta-analysis (source of the 'doubling').
- Actual result
- Children CD OR 2.75 (1.72-4.38) from few studies; the 2026 meta-analysis gives a smaller RR 1.59.
- Methodological quality
- moderate
- Relevance
- direct
- Limitations
- Older, fewer studies.
What does the overall evidence say?
Editorial assessment based on the studies above – not itself a study result.
Which position is better supported?
A consistent, moderate association between antibiotics and later Crohn's disease is well documented, including within families and after adjustment for infections; 'nearly doubling in children' overstates the most recent pooled estimate (about 1.6-fold).
Why some studies weigh more
Newest meta-analysis and infection-adjusted cohorts weigh most.
Is a causal relationship established? Possible, not established Consistent, dose-related, persists within families and after infection adjustment; reverse causation (prodromal symptoms) not fully excluded.
Remaining uncertainty
Size of the causal component.
Justified conclusion
Possible causal contribution of modest size; 'doubling' overstated.
Why do studies seem to disagree?
Ungaro (OR 2.75 in children) vs Størdal 2026 (CD RR 1.59): the newer review includes more studies; the older subgroup estimate was imprecise.
Does this depend on the country?
- General biological effects
- Universal biology.
- Eating habits
- Not applicable (medicine use, not diet).
- Legal rules
- Not applicable.
- Actual monitoring data
- Not applicable.
A regional difference that changes the conclusion is not supported by robust data.
Statistical re-check
- Magnitude vs 'doubling' – Children CD 1.59 (1.39-1.81) vs Ungaro 2.75 (1.72-4.38); all CIs log-symmetric. recalculated
Certainty of the overall evidence (GRADE, simplified)
- Main outcome
- Crohn's disease after antibiotic exposure
- Starting level
- low (observational studies)
- Reasons for downgrading
- risk of bias (reverse causation)
- Reasons for upgrading
- dose-response
- persists within siblings
- 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.
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 | TITLE:(antibiotic*) AND TITLE:("inflammatory bowel disease" OR "Crohn*" OR IBD) AND PUB_YEAR:[2019 TO 2026] | both directions | 67 |
Open questions
Causal designs (negative-control exposures, prodrome-lag analyses).
How deeply was this checked?
5 linked studies: 1 checked in full text (1 of them with a structured risk-of-bias assessment), 4 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)
New meta-analysis and infection-adjusted cohort support an association but show a smaller magnitude than 'nearly doubling'; verdict unchanged, wording sharpened.
New sources: I-ABX-118 I-ABX-119
In plain language
People who took more antibiotics were more often diagnosed later with Crohn's disease. The link also appeared when patients were compared with their own brothers and sisters, although it became weaker. This makes a real effect possible, but it is not proven, because early bowel symptoms may lead to antibiotic use before the diagnosis.
Studies on this claim
Studies supporting the claim (5)
-
Antibiotics and Crohn's disease (meta-analysis)
Ungaro R et al.. Am J Gastroenterol 2014 · PMID 25223575 · DOI 10.1038/ajg.2014.246Meta-analysiscited by the Tayebat archiveabstract checked★ key studyAntibiotic exposure was linked to higher odds of Crohn's disease, especially in children.
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?
Pool studies.
- How was the study done?
Meta-analysis.
- How many people, animals or samples were studied?
11 studies.
- What was actually found?
Higher CD odds.
- How large was the observed effect?
OR 1.74; children 2.75.
- What do the results mean in everyday life?
Association, not proof.
- What are the study's limitations?
Observational.
- What does it say about Elawady's specific claim?
Supports association.
- Do the results apply to Germany and Europe?
Moderate.
- What can explicitly not be concluded from this study?
Causation.
-
Childhood antibiotics and IBD (UK)
Kronman MP et al.. Pediatrics 2012 · PMID 23008454 · DOI 10.1542/peds.2011-3886Cohort studycited by the Tayebat archiveabstract checkedIBD was more common after antianaerobic antibiotics, but absolute rates remained low.
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?
Link.
- How was the study done?
Cohort.
- How many people, animals or samples were studied?
1.07 million.
- What was actually found?
Association.
- How large was the observed effect?
1.52 vs 0.83/10,000 PY.
- What do the results mean in everyday life?
Rare outcome.
- What are the study's limitations?
Confounding.
- What does it say about Elawady's specific claim?
Association.
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
Causation.
-
Antibiotics and IBD in adults (Sweden)
Nguyen LH et al.. Lancet Gastroenterol Hepatol 2020 · PMID 32818437 · DOI 10.1016/S2468-1253(20)30267-3Case-control studyindependent cross-checkfull text, structured risk-of-bias assessment★ key studyMore antibiotic use was linked to IBD, also when compared with siblings.
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?
Link.
- How was the study done?
Case-control with siblings.
- How many people, animals or samples were studied?
23,982 adult IBD cases, 117,827 controls, 28,732 siblings (Sweden 2007-2016).
- What was actually found?
More antibiotic prescriptions, especially broad-spectrum, were linked to higher odds of IBD: 3 or more vs none aOR 1.55 against the general population and 1.35 against siblings.
- How large was the observed effect?
aOR 1.55 (>=3 dispensations); 1.35 vs siblings; ever vs never 1.94.
- What do the results mean in everyday life?
Possible effect.
- What are the study's limitations?
Observational; reason for antibiotics unknown; adults only; no absolute risks.
- What does it say about Elawady's specific claim?
Supports association.
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
Causation, absolute risk, or effects in children.
-
Childhood antibiotics linked to later Crohn's disease
Størdal K et al.. Inflamm Bowel Dis 2026 · PMID 41617205 · DOI 10.1093/ibd/izaf324Meta-analysisindependent cross-checkabstract checkedPooled studies show about 59% higher relative risk of Crohn's disease after childhood antibiotics.
Children: CD RR 1.59, IBD RR 1.42 (association, not doubling)
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?
Pool studies on childhood antibiotics and IBD
- How was the study done?
Meta-analysis
- How many people, animals or samples were studied?
10 studies
- What was actually found?
Higher IBD risk, especially Crohn's
- How large was the observed effect?
CD RR 1.59 (1.39-1.81)
- What do the results mean in everyday life?
A moderate relative increase in a rare disease
- What are the study's limitations?
Observational
- What does it say about Elawady's specific claim?
Supports an association but not a doubling
- Do the results apply to Germany and Europe?
High
- What can explicitly not be concluded from this study?
Whether antibiotics cause IBD
-
Infant antibiotics linked to later IBD, not explained by infections
Mårild K et al.. Aliment Pharmacol Ther 2025 · PMID 39450871 · DOI 10.1111/apt.18358Cohort studyindependent cross-checkabstract checkedAntibiotics in the first year were linked to 33% higher relative risk of IBD after accounting for infections.
aHR 1.33 adjusted for infection frequency
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?
Separate effects of infections and antibiotics on IBD
- How was the study done?
Two birth cohorts
- How many people, animals or samples were studied?
103,046 children
- What was actually found?
Antibiotics, not infections, linked to IBD
- How large was the observed effect?
aHR 1.33 (1.01-1.76)
- What do the results mean in everyday life?
Possible modest effect
- What are the study's limitations?
Few cases
- What does it say about Elawady's specific claim?
Supports a possible effect, not a doubling
- Do the results apply to Germany and Europe?
High
- What can explicitly not be concluded from this study?
Proof of cause
No study in this group is marked as key.
Studies contradicting or limiting the claim (0)
No studies in this group.
Studies with mixed or unclear results (0)
No studies in this group.
Regional context
Germany / EU
Swedish data are EU-relevant (I-ABX-06).
Egypt
No Egyptian data were reviewed.
What applies in my country?
General scientific assessment
Potentially true Plausible and consistent association (about 1.4-1.6-fold in children), also within families; causation not established and 'nearly doubling' overstates the newest estimate.
This statement concerns biological or medical relationships. The scientific assessment above applies regardless of the country; country-specific food data do not change it.
References
- Antibiotics associated with increased risk of new-onset Crohn's disease but not ulcerative colitis: a meta-analysis.. Ungaro R et al.. Am J Gastroenterol 2014 · PMID 25223575 · DOI 10.1038/ajg.2014.246
- Antibiotic exposure and IBD development among children: a population-based cohort study.. Kronman MP et al.. Pediatrics 2012 · PMID 23008454 · DOI 10.1542/peds.2011-3886
- Antibiotic use and the development of inflammatory bowel disease: a national case-control study in Sweden.. Nguyen LH et al.. Lancet Gastroenterol Hepatol 2020 · PMID 32818437 · DOI 10.1016/S2468-1253(20)30267-3
- Systematic review and meta-analysis of childhood exposure to antibiotics and the subsequent risk of IBD.. Størdal K et al.. Inflamm Bowel Dis 2026 · PMID 41617205 · DOI 10.1093/ibd/izaf324
- Early-Life Infections, Antibiotics and Later Risk of Childhood and Early Adult-Onset Inflammatory Bowel Disease: Pooled Analysis of Two Scandinavian Birth Cohorts.. Mårild K et al.. Aliment Pharmacol Ther 2025 · PMID 39450871 · DOI 10.1111/apt.18358