Posted: Friday, May 14, 2021 14:21 Research in recent years has uncovered the vital importance of a person’s gut bacteria for things such as digestion and overall health. But there has been some controversy as to when bacteria begin to colonize a human. New research has found it happens during and after a baby’s birth and not before. The study was led by scientists at McMaster University in Hamilton, Ontario in collaboration with colleagues from Charité – Universitätsmedizin Berlin in Germany. The cientists collected stool samples from 20 babies delivered by Cesarean section. This excluded the transmission of bacteria that occurs naturally during a vaginal birth. “The key takeaway from our study is we are not colonized before birth,” said Katherine Kennedy, first author of the study and a PhD student. “Rather, our relationship with our gut bacteria emerges after birth and during infancy.”