Comment by wdbbdw

I dunno, after having had a front row seat to more than one vaginal birth I'd say that it's implausible to suggest that microbes aren't being transferred (via "vagina juice" and the proverbial "microbial organ", i.e. poop) from mother to baby. Also, having dabbled in microbial ecology in my professional life, I'd say that it's unlikely that said microbial transfer is inconsequential for the gut health of the baby. Doctors don't know everything, and I'd venture that effectively no research on the effects of a cesarian on the baby's gut health was done before the procedure became widespread.