Hi Evert, interesting presentation by Hank, Metamucil's Terry Crews .
Psyllium husks can indeed help with digestion. It's insoluble fibre, which means that it doesn't dissolve and our body doesn't absorb/digest it. Basically, what it does is make your stool soft and bulky. In Jake, that's the job of - depending on the product - oat fibre, inulin, guar gum and xanthan gum.