There is one upsetting thing about this article and discussion.

"Good" and "bad" bacteria. They have no morals, nor a concience. They are just bacteria. Neither are bacteria "friendly". Some live in the gut and digest food in a symbiotic environment. Some cause an imbalance and we suffer as our body expels them - either one new bacterium or an excess of what is marketed as "friendly" bacteria. But that isn't a moral judgement on bacteria, just as BFing or FFing doesn't make us "good" or "bad" mums, nor "friendly" mums - just mums.

(Sorry, this one does annoy me. I know, I know, geek.)