I am fascinated with the idea that a parasite might help with autoimmune disorders. In the UK studies have been conducted researching the effect on MS and crohn's disease.
I know it is creepy to think about, but the kind of worms they are talking about here do NOT reproduce or significantly grow in the host. They happily latch on and enjoy the ride and if you live in a place with even the most basic sanitation, the parasites will eventually die out. Tragic.
One study found that when the parasite was present, the immune system responded measurably. It shifted the T cell production toward a type of defender that is less likely to damage the body but could still effectively fight infection. What a way to embrace a new guest.
Some autoimmune disorders strike suddenly and have devastating effects before you could respond with this kind of therapy. It seems type 1 diabetes (maybe even type 2) would fall into this group. This would be a case where you need to show a commitment in advance--not in sickness but in health.
When the UK studies were finished and the experimental group was offered the drug to kill off the parasites, some participants said no thanks... they wanted to affirm their relationship. I'm sure the worms felt the same way.