Caesarean Section and Early Antibiotic Use Connected to Type 1 Diabetes

New study results show broad-spectrum antibiotic use within 2 years of life increases type 1 diabetes (T1D) risk in Caesarean-delivered children.

Recent research has linked antibiotics’ impact on gut microbiota to allergies, Crohn’s disease, autism, type 1 diabetes (T1D), and other diseases’ pathophysiology.

The hygiene hypothesis posits the immune system needs exposure to beneficial bacteria to develop properly. Broad-spectrum antibiotics (eg, extended-spectrum penicillins and macrolides) change the composition of the gut flora for months after therapy.

Previous research has shown perinatal inoculation with vaginal microflora provides a crucial base for a healthy gut. Babies delivered by Caesarean section aren’t afforded this inoculation, and noninoculated children receiving broad-spectrum antibiotics are most likely to have negative repercussions.

Now, new study results show broad-spectrum antibiotic use within 2 years of life increases type 1 diabetes (T1D) risk in Caesarean-delivered children.

The researchers culled 4 national databases for clinical data on all singleton births from 1997 to 2010. Pertinent data included antibiotic receipt, breadth of antibiotic spectrum, T1D or diabetic ketoacidosis inpatient diagnosis, and receipt of T1D standard-of-care medications. The study excluded children from multiple pregnancies (eg, twins) and children permanently lost to follow-up or diagnosed with T1D within the first 2 years of life.

In the study, Caesarean-delivered children who received broad-spectrum antibiotics in the first 2 years of life were at an increased risk of developing T1D. However, diabetes risk in children born vaginally was unaffected by broad-spectrum antibiotic receipt. This supports the idea that vaginal inoculation protects against conditions associated with disrupted gut flora. Maternal antibiotic use during pregnancy or lactation wasn’t associated with increased risk.

Most children received any antibiotics within the first 2 years of life, half received broad-spectrum antibiotics, and less than 0.2% developed T1D. Broad-spectrum antibiotic use has increased more than narrow-spectrum agents since 2005. Antibiotic therapy risk was similar among the different delivery method, birth weight, and gestational age cohorts. The incidence of T1D should be equal between groups if diabetes was associated with increased bacterial infection risk (the possible inverse causation).

Although the combination of Caesarean delivery and broad-spectrum antibiotic receipt increases the low baseline T1D risk significantly, the absolute added T1D risk is a slight 0.2%, meaning every 500 additional Caesarean deliveries lead to one additional T1D case. Maternal and paternal T1D history is many times more impactful than the combination of Caesarean birth and antibiotics.

Another Danish study found a statistically insignificant link between T1D and early antibiotic exposure. However, it focused on a small group of patients already diagnosed with T1D and didn’t differentiate among routes of birth delivery. Another Finnish case-control study associated phenoxymethyl penicilins, macrolides, and fluoroquinolones with T1D, while a different Dutch case-control study found T1D patients received more antibiotics than nondiabetics.

Overall, the health care industry should limit unnecessary Caesarean sections, as well as the use of extended-spectrum penicillins, macrolides, and other broad-spectrum antibiotics.


Clausen TD, et al. Broad-spectrum antibiotic treatment and subsequent childhood type 1 diabetes: a nationwide Danish cohort study. PLoS One. 2016;11(8):e0161654.