not because their immune system is immature, as is commonly believed: it’s because it is deliberately stifled to give microbes a free-for-all window during which they can establish themselves. But without the immune system’s full selective powers, how can a mammalian baby ensure that it gets the right communities? Its mother helps. Mother’s milk is full of antibodies which control the microbial populations of adults – and babies take up these antibodies during breastfeeding.
mother's milk and antibodies
