Table 1. Perturbations to the assembly of the neonatal microbiome, prevention strategies, and approaches for microbiome restoration.

Perturbation to microbiome assembly	Prevention strategies	Restoration approaches
C-section delivery	Support efforts to increase use of midwives Champion evidence-based labor management Optimize managing labor (reduce pain, increase maternal comfort) Educate women about the potential consequences of C-section delivery Change policies around physician incentives and malpractice insurance	Inoculation of neonate with maternal vaginal flora immediately following C-section delivery Breastfeeding Pre- and probiotic supplementation of neonate
Gestational, perinatal, or postnatal antibiotics	Implement robust antimicrobial stewardship programs (http://www.whitehouse.gov/the-press-office/2014/09/18/executive-order-combating-antibiotic-resistant-bacteria) Develop safe strategies that limit use of antibiotics in women in labor (e.g., rapid PCR testing for group B Streptococcus at the time of admission to the delivery unit) During C-section delivery, give antibiotics after cord clamping to eliminate fetal exposure to antibiotics Use more prudency in antibiotic administration during pregnancy	Breastfeeding Pre- and probiotic supplementation of mother during pregnancy and neonate after birth
Formula feeding	Adopt WHO/UNICEF Baby Friendly Hospital Initiative Develop other policies that incentivize breastfeeding Do not offer formula to newborns without request or medical indication Promote use of donor breast milk rather than formula when maternal milk is not an option	Reintroduce breastfeeding Pre- and probiotic supplementation