Table 1 Maternal and neonatal exclusion criteria

Maternal exclusion criteria

 Delivery < 37 weeks gestation

 Aged ≤17 years

 Body mass index ≥ 25

 Antibiotic use during pregnancy

 Antibiotic use during labour (group C)

 Immunosuppressive use within 3 months prior to delivery

 Inflammatory bowel disease

 Coeliac disease

 Rupture of membranes before CS (groups A and B)

 Rupture of membranes > 18 h (group C)

 Diabetes mellitus type I or II

 Gestational diabetes requiring insulin

 History of gastro-intestinal surgery

 Alcohol or tobacco use in second or third trimester

 Use of recreational drugs during pregnancy

 Maternal antibiotic use during first month of neonatal life

Neonatal exclusion criteria

 Congenital gastro-intestinal anomalies

 Gastro-intestinal surgery during first month of life

 Antibiotic or immunosuppressive medication use during first month of life