Could be because in those cases they also did not give them probiotics. When antibiotics were first used they gave probiotics during and after to replenish good bacteria they knew would also die off. They don’t do that anymore.
“When antibiotics were first used they gave probiotics during and after to replenish good bacteria they knew would also die off. They don’t do that anymore.”
I have never heard this - where did you get this information? I was under the impression that the whole concept of probiotics was relatively recent, in the last 10-15 years or so.