It's a mouse study, and genetically tweaked mice at that... From the sound of the summary, it sounds like it should be directly examined in humans. Until there's a human confirmation, I don't think it's worth a discussion post.
Not exactly something that's easy to confirm in humans. Of course the mice were genetically tweaked, it would be ... hard to measure an effect of a genetic factor without having experimental groups differing in that factor in a closely defined way.
Is the conclusion speculative? Absolutely. Then again, so is a lot of what we're discussing around here, and there is a reason the study made it into Nature (Impact Factor of 36).
If it's worth saying, but not worth its own post, even in Discussion, it goes here.