Inclusion Criteria  Pregnant women:  Enrolled at Aarhus University Hospital Singleton pregnancy Age above 18 years at informed consent Aim to give birth vaginally Aim to breastfeed No use of probiotics (contained in dietary supplements/ food) after written consent.  Infants:  1. Gestational age between 37-42 weeks  Exclusion Criteria:  Pregnant women • Use of immunosuppressant drugs.  Infants:  • None