Unfortunately, this late in the game it’s going to take much more than just supplemental Nattokinase. He would have to do a complete overhaul in diet and supplements in order to allow the body to heal, and even then it’s questionable. Look into Keto + Intermittent Fasting. There are some really good docs on YouTube that show you how to do it— look up Dr. Berg, Dr. Boz and Dr. Sten Ekberg (he’s my favorite and he has a practice in Georgia where he sees patients). They’re very informative about healing lots of different issues.
People on TS rave about this guy. His protocols are tough but lots of testimonials. Maybe investigate it and see what you think for your friend?
https://floridasharkman.org/category/diseases/