I'm skeptical, but not yet to the point of finding it impossible. First of course: Correlation != Causation. Affluent families will eat different foods than p

I'm skeptical, but not yet to the point of finding it impossible. First of course: Correlation != Causation. Affluent families will eat different foods than poor families, but will also have more opportunities for cognitive development. So maybe this result is: Just in! Rich folk eat different stuff than poor folks. Second: the sample size is smallish. Not laughably smallish. But given the complexity of the microbiome, couldn't you predict pretty much anything? I'd suspect that after a random permutation of inputs and output, you could still predict anything. Probably, they controlled for this, but I'm still looking for the paper. Third: The age range from 40 days to 10 years is so large, huge changes will occurs in the microbiome in that time frame. Is there a magic thing, already in the gut of a 40 day year old baby, and still there 10 years later, that predicts brain size? That seems unlikely. update: Found the paper, still have to read it though. https://www.biorxiv.org/content/10.1101/2020.02.13.944181v5.full.pdf https://www.biorxiv.org/content/10.1101/2020.02.13.944181v5....