I can&#x27;t be bothered to write a complete takedown, but two things come to mind:<p>1) The author falls prey to the naturalistic fallacy:<p>&gt; We can actually achieve a good mixture of gut bacteria very similar to that of our hunter-gatherer ancestors by adopting a good diet high in fiber and low in processed foods.<p>2) I&#x27;ve read studies to the effect that some infectious diseases can affect intelligence. Particularly when children are young - apparently there is a mechanism to either further develop the immune system or the brain depending on the environment (this might partially explain the Flynn Effect). I can&#x27;t find the exact study (this used to be in this section - <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Impact_of_health_on_intelligence#Infectious_diseases" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Impact_of_health_on_intelligen...</a> - but I think it was edited out at some point).