Re: “Vaginal seeding” of infants born by caesarean section - we should offer women safer options
The recent paper by Cunnington et al.  raises concerns about the risk of transmission of serious infections that is posed by the practice of ‘vaginal seeding’ for infants who are born by Caesarean section. This practice involves exposing these infants to vaginal fluids post-delivery and therefore to similar microbiota as infants born vaginally. Caesarian section delivery has been associated with various problems such as autoimmune and allergic diseases later in childhood which are thought to be related to this difference in microbiota exposure. A recent study suggests microbiota can be partially restored in these infants by vaginal microbial transfer therefore in principle providing scientific support for the practice of ‘vaginal seeding’. 
Potentially serious infection in infants is a real risk and I think we should aim at providing safer alternatives to restore microbiota in infants born by Caesarian section.
Methods that have been proposed by some authors include administering probiotics to infants born by Caesarian section and encouraging breastfeeding. Breastmilk contains lactobacilli and bifidobacteria. Where breast milk is not feasible, probiotic containing milk formula can be used.  There is need for research into the appropriate strains of probiotics to ensure safety and efficacy.
Women who elect to use ‘vaginal seeding’ should be made aware of the risk of infection and should be assisted to make informed choices based on their medical history.
For example women who are known to carry or are at high risk of HIV, herpes simplex infection, chlamydia infection or have had a previous infant with Group B streptococcal septicaemia should be strongly discouraged from exposing their infants to vaginal fluids. Whether or not we should be advocating a blanket ‘ban’ on ‘vaginal seeding’ needs further scientific research as one might argue that the risks of infant exposure to harmful organisms in the majority of cases is similar to vaginal birth. 
1. Cunnington Aubrey J, Sim Kathleen, Deierl Aniko, Kroll J Simon, Brannigan Eimear, Darby Jonathan et al. “Vaginal seeding” of infants born by caesarean section BMJ 2016; 352 :i227
2. Neu J, Rushing J. Cesarean versus Vaginal Delivery: Long term infant outcomes and the Hygiene Hypothesis. Clinics in perinatology. 2011;38 (2):321-331. doi:10.1016/j.clp.2011.03.008.
3. Dominguez-Bello MG, De Jesus-Laboy KM, Shen N, Cox LM, Amir A, Gonzalez A et al. Partial restoration of the microbiota of Caesarian-born infants via vaginal microbial transfer. Nat Med, Feb 1 2016. doi: 10.1038/nm.4039. [Epub ahead of print]
4. Mueller NT, Bakacs E, Combellick J, Grigoryan Z, Dominguez-Bello MG. The infant microbiome development: mom matters. Trends in molecular medicine. 2015;21(2):109-117. doi:10.1016/j.molmed.2014.12.002.
Competing interests: No competing interests