I think that the Uzumaki clan was defeated by no one but Madara. He got the DNA from the corpses. He implantes the Uzumaki DNA and Senju(from Hashi) in the 10-tails former body(well, as you maybe noticed, Gedou Mazou has some similarities with 10-tails, and I think it is really the 10-tails body).
So, I think this is why the Gedou gives him longevity.
Thoughts?