On Feb 1, NPR reported on small study conducted at NYU and published in Nature magazine that reported success in giving babies delivered by c-section a microbiome similar to babies delivered vaginally. In recent years many scientists have come to suspect that the reason that babies delivered via c-section have more risk for immune system-related disorders (asthma, excema, Type 1 diabetes, etc) is because they don't get the same boost from their mother's microbiome. Many also think that the trend towards more c-sections in the last decades might be playing a role in the marked increase in immune systems disorders.
While many parents can avoid a c-section - if it is being done for the doctor's/patient's convenience, socio-cultural norms, etc - parents of multiples typically don't have a choice. The study showed very consistently that babies swabbed with a gauze saturated with the mother's vaginal microbes immediately after birth had a microbiome close to that of vaginally delivered babies. While scientists caution parents to not try this at home (!), one of the scientists interviewed did say that she had her OB-GYN do it for her baby. The scientist had to have a c-section! So if you might be scheduled for a c-section, have a chat with your doctor!