Relation Between Infant Microbiota and Autism?: Results from a National Cohort Sibling Design Study

Area of Science:

• Pediatric Health
• Microbiome Research
• Neurodevelopmental Disorders

Background:

• Investigating potential adverse effects of infant microbiota changes on autism risk.
• Addressing challenges of unobserved confounding in microbiota research.
• Utilizing a sibling study design to mitigate confounding factors.

Purpose of the Study:

• To examine the association between cesarean delivery and antibiotic use in infancy with autism risk.
• To address unobserved confounding using advanced statistical models.
• To determine if surrogate markers for microbiota changes impact autism susceptibility.

Main Methods:

• Population-based prospective cohort study of Danish live births (1997-2010).
• Exposure variables: cesarean delivery and antibiotic use in the first two years of life.
• Analytical models: between- and within-sibling models, sibling-stratified Cox models, and standard Cox models.

Main Results:

• Standard models suggested increased autism risk with cesarean delivery and antibiotics.
• Sibling-stratified models indicated broader spectrum antibiotics increased autism risk (HR=1.16).
• Between-within sibling models found no significant association for cesarean delivery or antibiotic use with autism risk.

Conclusions:

• The between-within sibling model provided more precise and valid estimates.
• Results do not support a causal relationship between infant antibiotic treatment, cesarean delivery, and autism.
• Findings suggest that common exposures like antibiotics and delivery mode are unlikely to be causal factors for autism.