Reacción a "Reactions: study explores how reduced microbiota transfer between mothers and babies born by c-section is compensated"

This study complements previous ones on the transmission of the microbiome from mother to baby. We know that, during childbirth, we acquire the first bacteria that will form our microbiome, which plays a very important role in our health. As a result, babies born by caesarean receive fewer bacteria from their mothers’ gut microbiome than those born vaginally.

In this study, the authors analyse various types of samples from 120 mothers in the Netherlands (faeces, milk, skin, vaginal, saliva...) to study the contribution of these microbiomes in shaping the baby’s microbiome. In terms of the number of samples, the study extends the one published by Ferretti et al. in the same journal in 2018, in which only babies born vaginally were included. The main conclusion of the study is that the lower transmission of the mother’s gut microbiome in babies born by caesarean section may be compensated for by the mother’s other microbiomes. But in terms of methods, the technique used is problematic: the authors only sequenced part of the 16S gene of the bacteria, instead of sequencing whole genomes, as other transmission studies have done to date. Thus, the resolution obtained is limited, and it is not possible to speak unequivocally of transmission.
Regarding the press release, the title Whether born naturally or via caesarean section, babies receive essential microbes from their mothers is something we already knew: babies born via caesarean section receive fewer intestinal microbes from their mothers, but they do receive some.