No, it fits an existing pattern. Something commonplace in our natural environment that we adapted to over millions of years and exerted a non-obvious influence that wasn't scientifically verified until recently. Dietary fiber is but one example.

I'm not saying that's "evidence", or that the posted study is valid, but I'm also not aware of any robust studies demonstrating no difference from placebo. A lack of good data is neither positive nor negative.

As for dietary fiber, it wasn't broadly seen as useful for anything other than constipation until the 1970s when it was shown that increased fiber intake reduced colon cancer risk