The sarcasm is unhelpful and detracts from any potential discussion. Old articles and stories show up here all the time, simply because they are interesting and worth discussion.

A more useful/helpful reply would be to note that this article should be tagged (2013).

Really tired of getting excited by headlines like this on HN only to find that the article is really old. Posting super old articles like this is much more unhelpful than my sarcastic comment. I hope this practice changes.

I agree. I've read a lot about gut bacteria and there's nothing new here. I'm sure some haven't seen it before, so posting it is fine, but it did get my hopes up that something new was discovered or something.

Your excessive exuberance is not a hacker news problem, per se.

Interesting article, BUT yes, it would be nice if a date was added to the article title.