Restoration of Microbiota in Neonates

Inclusion Criteria: * Infants of healthy mothers with uncomplicated pregnancies at term, mothers of any ethnic or social background that can speak, read, and understand Swedish to the extent that they can consent in Swedish. An additional inclusion criterion for mothers in the CS groups is vaginal pH ≤ 4 at the time of birth. Exclusion Criteria: * Infants of mothers with pre-eclampsia or complicated pregnancies, mothers \<18 years or \>40 years of age, genital herpes simplex, genital warts, HIV, Hepatitis B or complications during delivery, infants delivered prior to 37 weeks of gestation. Additional exclusion criteria for mothers in the CS group: Mothers positive to Group B Streptococcus, Group A Streptococcus, bacterial vaginosis, vaginal pH \> 4 at the time of birth. Mothers with fecal samples positive for Salmonella, Shigella, Campylobacter or Yersinia.