Compliments of Wilbur, a great resource for anyone wanting to know a bit more about the human gut:
Gut Health in Early Life: Significance of the Gut Microbiota and Nutrition for Development and Future Health.
I will be out of town (and off-line!) until Tuesday. There will be a 20 question test when I return.
Takes about 15 minutes to read, if you are a fast reader. Really good explanations about how the gut obtains new bacteria from birth on.