Nezam El-Tayebat Fact CheckA scientific assessment of the “نظام الطيبات” nutrition system
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Unclear / insufficient evidence Overinterpreted Certainty of evidence: low provisional C-ABX-06

Antibiotic exposure in early life causes asthma and allergic disease.

In short: Overstated: early antibiotics are linked to childhood asthma, but sibling studies and analyses by type of infection suggest much of the link reflects early respiratory symptoms and family factors; causation is not established, and the allergy link largely disappears within families.
Conclusion: Association exists, but sibling studies suggest much of it reflects early respiratory symptoms and family factors; causation unclear, and the allergy link largely disappears within families.
  1. Original statement
  2. Scientific assessment
  3. Scientific evidence in detail
  4. In plain language
  5. Studies on this claim
  6. Regional context
  7. What applies in my country?
  8. References

Original statement

No Arabic original wording available.

Translation

Antibiotic exposure in early life causes asthma and allergic disease.

Origin

Source status
Archive editors
Attribution
Archive editors (eltayebat.com)
Origin
https://eltayebat.com/rule/antibiotic-overuse/
Attribution uncertainty
Archive summary ('linked to ... asthma') and bibliography (A-ABX-04, A-ABX-05, A-ABX-06); no direct Elawady quote found on asthma.
Claimed mechanism

Microbiome disruption during immune development.

Claimed health effect

Asthma, eczema, hay fever.

Population concerned

Children

Geographic restriction by Elawady

none found

Scientific assessment

Unclear / insufficient evidence – The data do not allow an assessment either way.

Certainty of evidence: low – Further research is likely to change the assessment considerably.

1. What was claimed?

Antibiotics cause asthma.

2. What is demonstrably correct?

Associations: ALSPAC OR 1.75 (1.40-2.17) with dose-response (A-ABX-04); US cohort aOR 1.52 (1.07-2.16) (A-ABX-05); Canadian cohort small risk increasing with courses (A-ABX-06). Meta-analysis of 52 studies: OR 1.37 (1.29-1.45), 1.19 (1.11-1.28) in studies addressing reverse causation and confounding by indication (I-ABX-115). Danish sibling analysis: asthma association reduced but persisting (HR 1.52 -> 1.24, 1.16-1.34), also for eczema (I-ABX-114).

3. What is wrong or exaggerated?

Örtqvist et al. (n=493,785; sibling analysis): fetal exposure HR 1.28 in cohort but 0.99 (0.92-1.07) in sibling analysis; antibiotics for urinary/skin infections HR 0.85 (0.47-1.55) in siblings; when analyses were restricted to first-year exposure and asthma from age 2, the sibling associations disappeared for all antibiotic groups (I-ABX-03). In the Danish sibling analysis, allergy (rhinitis HR 0.91; drug-defined allergy 1.04) and asthma starting after age 5 (1.04, 0.93-1.16) were not associated (I-ABX-114). The strongest associations occur with short time lags, typical of reverse causation (I-ABX-115). 'Causes' is therefore not established, and the allergy part is not supported within families.

4. What remains unclear?

Residual effect for respiratory-infection antibiotics in sibling analysis (HR 2.36) may still reflect confounding by indication.

5. Which studies support it?

A-ABX-04, A-ABX-05, A-ABX-06, I-ABX-115; partly I-ABX-114 (asthma and eczema associations persist within siblings).

6. Which studies contradict it?

I-ABX-03 (Swedish sibling analysis), I-ABX-114 (no within-family association for allergy or later-onset asthma).

7. What applies to Germany and Europe?

The decisive sibling analysis is Swedish (I-ABX-03) and ALSPAC is British (A-ABX-04); both are directly relevant to Europe.

8. What is known about Egypt?

No Egyptian data were reviewed.

9. What practical conclusion is appropriate?

The asthma link is not good evidence against necessary antibiotic use.

Assessment details

Rationale for certainty of evidence

Dose-dependent associations exist, but a large Swedish sibling analysis showed the association with prenatal antibiotics disappeared and childhood associations were strongly attenuated, consistent with confounding by familial factors and respiratory infections (confounding by indication / protopathic bias).

Source quality

Archive cites three cohort studies, all observational.

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 in early life cause childhood asthma and allergic disease?

Research question in detail (PECO)
Population
Infants and children
Intervention or exposure
Antibiotics in the first year(s) of life
Comparison
No exposure; siblings
Geographic scope
Universal biology
Outcomes
  • Asthma
  • Allergy/eczema

Study results as reported by the authors. Our assessment follows below.

What speaks for the claim?

What speaks against the claim?

What does the overall evidence say?

Editorial assessment based on the studies above – not itself a study result.

Which position is better supported?

A modest association with asthma persists in some within-family analyses, but it is largely absent for allergy and for asthma diagnosed after age 5 or for antibiotics given for non-respiratory infections; causation is not established.

Why some studies weigh more

Sibling designs and analyses by indication weigh most; the pattern (effects for respiratory-infection antibiotics and early asthma only) points to reverse causation and confounding by indication.

Is a causal relationship established? Possible, not established Microbiome effects during immune development are plausible, but the indication-specific pattern argues for confounding.

Remaining uncertainty

Whether a small residual effect is causal.

Justified conclusion

Association yes; causation unclear.

Why do studies seem to disagree?

Brandt 2025 (asthma association persists in siblings) vs Örtqvist 2014 (largely disappears): Brandt did not stratify by indication, while Örtqvist showed no association for antibiotics given for urinary or skin infections - consistent with respiratory symptoms of early asthma being treated with antibiotics.

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
  • Attenuation within siblings – Asthma log-excess reduced by about 49% (1.52 -> 1.24); asthma after age 5 null (1.04, 0.93-1.16). recalculated
  • Attenuation with bias control – 1.37 -> 1.19 (about 45% of the log-excess removed); CIs log-symmetric. recalculated
Certainty of the overall evidence (GRADE, simplified)
Main outcome
Childhood asthma after early antibiotics
Starting level
low (observational studies)
Reasons for downgrading
  • risk of bias (confounding by indication, reverse causation)
  • inconsistency between sibling studies
Reasons for upgrading
  • dose-response
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).

DatabaseDateSearchLooking forHitsIncluded
Europe PMC26 October 2026TITLE:(antibiotic*) AND TITLE:(asthma OR wheez* OR allerg* OR atopic) AND (sibling OR "meta-analysis" OR "systematic review" OR "confounding by indication") AND PUB_YEAR:[2015 TO 2026]both directions123
Europe PMC26 October 2026(antibiotic*) AND (asthma) AND (infan* OR "early life" OR childhood) AND ("sibling analysis" OR "sibling comparison" OR "sibling design" OR "sibling-controlled")contradicting evidence83

Open questions

Sibling analyses stratified by indication.

How deeply was this checked?

6 linked studies: 2 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
  1. 25 October 2026 · Phase 1 · Initial assessment: Unclear / insufficient evidence (low)
  2. 26 October 2026 · Phase 4 (systematic evidence review) · Re-examined with extended evidence; verdict unchanged: Unclear / insufficient evidence (low)
    New evidence (I-ABX-114, I-ABX-115) shows a partly persisting asthma association but no allergy association within families; this does not resolve causality, so the verdict stays.
    New sources: I-ABX-114 I-ABX-115

In plain language

Children who received antibiotics as babies have asthma more often. But children who later develop asthma often have chest symptoms early and get antibiotics for them. A large Swedish study compared siblings and found that much of the link disappeared. So it is not clear whether antibiotics cause asthma.

Studies on this claim

Studies supporting the claim (4)

  • Infant antibiotics and asthma (UK)

    Hoskin-Parr L et al.. Pediatr Allergy Immunol 2013 · PMID 24299467 · DOI 10.1111/pai.12153
    Cohort studycited by the Tayebat archiveabstract checked

    More antibiotic courses were linked to more asthma at age 7.

    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 to asthma.

    How was the study done?

    Cohort.

    How many people, animals or samples were studied?

    4952.

    What was actually found?

    Dose-response.

    How large was the observed effect?

    OR 2.82 (4+).

    What do the results mean in everyday life?

    May be confounded.

    What are the study's limitations?

    Reverse causation.

    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.

    Scientific details →

  • Early antibiotics and asthma (US)

    Risnes KR et al.. Am J Epidemiol 2011 · PMID 21190986 · DOI 10.1093/aje/kwq400
    Cohort studycited by the Tayebat archiveabstract checked

    Antibiotics before 6 months were linked to asthma at age 6.

    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?

    1401.

    What was actually found?

    Association.

    How large was the observed effect?

    OR 1.52.

    What do the results mean in everyday life?

    Uncertain.

    What are the study's limitations?

    Small.

    What does it say about Elawady's specific claim?

    Association.

    Do the results apply to Germany and Europe?

    Moderate.

    What can explicitly not be concluded from this study?

    Causation.

    Scientific details →

  • Antibiotics and asthma (Canada)

    Marra F et al.. Pediatrics 2009 · PMID 19255032 · DOI 10.1542/peds.2008-1146
    Cohort studycited by the Tayebat archiveabstract checked

    Infant antibiotics were linked to a small increased asthma risk.

    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?

    251,817.

    What was actually found?

    Small risk.

    What do the results mean in everyday life?

    Small.

    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?

    Moderate.

    What can explicitly not be concluded from this study?

    Causation.

    Scientific details →

  • Infant antibiotics linked to childhood asthma, less so after accounting for bias

    Zhang Z et al.. World Allergy Organ J 2021 · PMID 34934469 · DOI 10.1016/j.waojou.2021.100607
    Meta-analysisindependent cross-checkabstract checked

    Pooled data: about 37% higher odds, 19% when bias is addressed.

    OR 1.19 in studies addressing reverse causation/confounding by indication

    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 infant antibiotics and asthma

    How was the study done?

    Meta-analysis

    How many people, animals or samples were studied?

    52 studies

    What was actually found?

    Association persists but weakens

    How large was the observed effect?

    OR 1.37; 1.19 in better studies

    What do the results mean in everyday life?

    Small possible effect

    What are the study's limitations?

    Observational

    What does it say about Elawady's specific claim?

    Supports an association, not proof of cause

    Do the results apply to Germany and Europe?

    Moderate

    What can explicitly not be concluded from this study?

    Whether antibiotics cause asthma

    Scientific details →

Studies contradicting or limiting the claim (1)

  • Antibiotics and asthma: sibling comparison (Sweden)

    Örtqvist AK et al.. BMJ 2014 · PMID 25432937 · DOI 10.1136/bmj.g6979
    Cohort studyindependent cross-checkfull text, structured risk-of-bias assessment★ key study

    When siblings were compared, most of the antibiotic-asthma link disappeared.

    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 confounding.

    How was the study done?

    Sibling analysis.

    How many people, animals or samples were studied?

    493,785 children.

    What was actually found?

    Fetal antibiotic exposure: HR 1.28 in the whole cohort, 0.99 when comparing siblings. Antibiotics for urinary/skin infections: 1.54 vs 0.85 in siblings. Antibiotics for respiratory infections remained linked (2.36 in siblings), likely because of the infections themselves.

    How large was the observed effect?

    Fetal HR 0.99 in siblings.

    What do the results mean in everyday life?

    Antibiotics probably not the main cause.

    What are the study's limitations?

    Reason for prescriptions not recorded; short follow-up (to about age 6); fewer informative sibling pairs for some comparisons.

    What does it say about Elawady's specific claim?

    Contradicts causal claim.

    Do the results apply to Germany and Europe?

    High.

    What can explicitly not be concluded from this study?

    That antibiotics cause asthma; a small effect cannot be fully excluded.

    Scientific details →

Studies with mixed or unclear results (1)

  • Danish siblings: early antibiotics not linked to overweight, weakly to asthma

    Brandt S et al.. BMJ Med 2025 · PMID 40519361 · DOI 10.1136/bmjmed-2024-001064
    Cohort studyindependent cross-checkfull text checked★ key study

    Comparing siblings, the link with overweight vanished and the link with asthma halved.

    Asthma: adjusted HR 1.52 -> sibling 1.24; allergy null within 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?

    Test links between baby antibiotics and later diseases

    How was the study done?

    National registers with sibling comparison

    How many people, animals or samples were studied?

    518,483 children

    What was actually found?

    Most links weakened within families; asthma and eczema remained

    How large was the observed effect?

    Overweight sibling HR 1.02; asthma sibling HR 1.24

    What do the results mean in everyday life?

    Family factors explain much of the earlier findings

    What are the study's limitations?

    Overweight only from hospital records

    What does it say about Elawady's specific claim?

    Contradicts antibiotics causing obesity; partly supports an asthma link

    Do the results apply to Germany and Europe?

    High

    What can explicitly not be concluded from this study?

    Causality for asthma

    Scientific details →

Regional context

Germany / EU

The decisive sibling analysis is Swedish (I-ABX-03) and ALSPAC is British (A-ABX-04); both are directly relevant to Europe.

Egypt

No Egyptian data were reviewed.

What applies in my country?

General scientific assessment

Unclear / insufficient evidence Association exists, but sibling studies suggest much of it reflects early respiratory symptoms and family factors; causation unclear, and the allergy link largely disappears within families.

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

  1. Antibiotic exposure in the first two years of life and development of asthma and other allergic diseases by 7.5 yr: a dose-dependent relationship.. Hoskin-Parr L et al.. Pediatr Allergy Immunol 2013 · PMID 24299467 · DOI 10.1111/pai.12153
  2. Antibiotic exposure by 6 months and asthma and allergy at 6 years: Findings in a cohort of 1,401 US children.. Risnes KR et al.. Am J Epidemiol 2011 · PMID 21190986 · DOI 10.1093/aje/kwq400
  3. Antibiotic use in children is associated with increased risk of asthma.. Marra F et al.. Pediatrics 2009 · PMID 19255032 · DOI 10.1542/peds.2008-1146
  4. Association of infant antibiotic exposure and risk of childhood asthma: A meta-analysis.. Zhang Z et al.. World Allergy Organ J 2021 · PMID 34934469 · DOI 10.1016/j.waojou.2021.100607
  5. Antibiotics in fetal and early life and subsequent childhood asthma: nationwide population based study with sibling analysis.. Örtqvist AK et al.. BMJ 2014 · PMID 25432937 · DOI 10.1136/bmj.g6979
  6. Use of antibiotics in early life and development of diseases in childhood: nationwide registry study.. Brandt S et al.. BMJ Med 2025 · PMID 40519361 · DOI 10.1136/bmjmed-2024-001064

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