Your comment was 100% correct. To go deeper into the unpredictable aspects of the human body would be futile on this forum. It would require a different thread for each system of the human body and yet another for the body as a whole.
We can discuss it. We have only begun to touch upon the intricacy of the bodies multiple systems and their multiple interactions.
I can't cut and paste from a PDF, but the word unpredictable first appears in the second paragraph.
http://physics.oregonstate.edu/~stetza/ph407H/Chaos.pdf
http://glimmerveen.nl/le/chaos.html
The complexity and ,yes, unpredictability of the human body are well beyond algorithmic-based clinical trials.