> There's an growing body of evidence that suggests early microbial exposure is required for proper immune development Yes. But that's not linked to "seeding"

> There's an growing body of evidence that suggests early microbial exposure is required for proper immune development Yes. But that's not linked to "seeding" which doesn't have any conclusive evidence to back that up(yet) compared to colostrum/breastfeeding[1] I'm aware of one study that has tried seeding. It's hypothesised, but needs much more research before being counted/discounted > Women have been giving birth since creation with minimal enough problems for humans to survive and succeed as a species Yes, but up until decent, clean deliveries with the option of c-section, and anti-biotics child birth killed 5% of mothers[2]. Bear in mind that without birthcontrol (pills or condom) most women would have about 6 pregnancies in their life time. [3] my bad maths makes that a ~1/4 chance of dying in childbirth/complications arising from. The study that link obecity and asthma to c-section is small[4] however it is worth widening and expanding to more than scotland. Brazil would be a good target as 50+% of births are c-section. [1]https://www.nhs.uk/news/pregnancy-and-child/breast-milk-raises-immunity/ https://www.nhs.uk/news/pregnancy-and-child/breast-milk-rais... The only link I could find that wasn't selling something (either hippy nonsense or a drug) [2]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1633559/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1633559/ [3]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3865739/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3865739/ [4]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5055095/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5055095/ TL;DR: 5% of child births were fatal to the mum, modern medicine has made that drop to <0.1%. There is some evidence that you might be fatter if you were born by optional c-section. However this is a limited study in one country.