No matter how many sloppy kisses we give the car window, if we are allowed to kiss and cuddle with our mothers regularly, we will be protected by her microbes. Breastfeeding also promotes particular members of our gut flora — breast-milk-loving Bifidobacteria, for example. Colonising the gut so early, these bacteria are instrumental in the development of later bodily functions, such as those of the immune system or the metabolic system.
