Not OP. In many cases, the genetic modifications are either performed to either let the plant produce (more) lectins that kill insects, or make the plant immune to certain herbicides like glyphosate. The human gut and microbiome might be able to deal with lectins they have evolved to deal with, and in “normal” quantities. But those additional GMO lectins are suspected to be hard on the intestinal barrier. If that barrier is compromised, autoimmunity might be the result, as OP indicated.