Anyone trying to discredit this because he discusses "leaky gut," be aware that "leaky gut" and "leaky gut syndrome" are two different things, with the latter being the pseudoscientific nonsense. In this podcast he's talking about the very real phenomenon of intestinal hyperpermeability. According to the Wikipedia page for Leaky Gut Syndrome:

Unlike the scientific phenomenon of increased intestinal permeability ("leaky gut"), claims for the existence of "leaky gut syndrome" as a distinct medical condition come mostly from nutritionists and practitioners of alternative medicine.

Also, to further explain the difference between the two, check here:

https://my.clevelandclinic.org/health/diseases/22724-leaky-gut-syndrome#:~:text=But%20some%20people%20have%20increased,molecules%20through%20%E2%80%94%20potentially%20toxic%20ones