Comment by bnralt

But why did they decide that? It seems to be a pretty clear example of the perfect being the enemy of the good.

1. Better bacteria is found in the wild, it might be able to significantly reduce cavities. People could be randomly passing it to others through kissing, and no one is concerned about it since it doesn't seem to be harmful.

2. It’s not given to people for replacement therapy because (as the article states) people decided that a replacement therapy “needs to meet a number of criteria."

3. Except meeting that criteria makes people think the replacement isn’t safe and shouldn’t be tried.

The article is saying “of course we needed to add X characteristics to the bacteria, they were necessary in order for it to be a good replacement” and then goes on to say “of course people shouldn’t be using the bacteria with X characteristics, X characteristics might be dangerous.”