He is correctly citing the damage done by lectin proteins to the gut lining. He is simultaneously discounting the benefits of lycopene (for example) found in tomatoes. Most of the latter's toxins are in the seeds, which are strained out in making sauces.
In other words, nutrition is complex, and the maxim "the poison is in the dose" is to be taken seriously. Balance is necessary. Life is fatal anyway. Etc.
He is correctly citing the damage done by lectin proteins to the gut lining.
Gundry is a charlatan and saying tomatoes, eggplants, and peppers are bad for you should be proof enough of that. How can anyone believe a word he says at that point? He also says that fruit causes type 2 diabetes -- calls them toxic candies or some other fear porn phrase. Zero evidence to back that up. As if all the fat type 2s are that way because they ate too much fruit.
As far as lectins go, cooking neutralizes lectins ... and I don't know anyone who eats beans or lentils raw. The most long-lived societies on the planet are grain and bean eaters ... and I'm guessing tomatoes and eggplants are probably also in their diet as well.
Sorry, these quack diet guys get me going. The blood type diet guy D'Adamo (zero evidence for his theories as well), Gundry with his lectin screed - both promoting nonsense and sell garbage "supplements" (of course) - are shameless con men.
I’m sure if you buy everything Goop sells and follow them, you can live forever. Or if you follow that Tech CEO guy, I can’t think of his name. Can you? Is he the one who always gets blood transfusions?