I wasn't familiar with vaginal seeding, although the concept sounds reasonable. What I thought was odd was the author of the article referred to the mother of his child as his "partner." He cared enough to swab his baby with her vaginal microbes, but not enough to marry the child's mother? At least the drawing of a pregnant woman with the article calls her a "mother."
So I e-mailed him and asked.
Definition: The term vaginal seeding, also called microbirthing, describes wiping
babies with vaginal fluid after they have been born by Cesarean. The
belief is that this boosts poorly-defined beneficial gut microbes that
keep our immune systems healthy and so may reduce the risk of developing
conditions such as asthma, food allergies, and hay fever in later life. (Science 2.0)